I'm pretty sure I could answer most of the examples after watching you work it out a few minutes. Then I look at my homework and it doesn't even look similar
Thanks for all the vids. You've helped me to understand every inch of this subject, something my teacher has so far failed to do. In turn you've helped me earn a GPA which has rewarded me with full tuition to any school I want :) Great job!
@danyhighmonster In official mathematical lingo, e is Euler's number so I would assume in this video it is Euler's number. e = 2.71 roughly. The base of the Napierian logs.
thank you for explaining the FULL equation. i was wondering why in the book and in the lecture that when the powers got more complicated that just x, that they tacked on some random shit. Why the hell would they shorten the equation? i think the WHOLE fucking equation is important AT ALL TIMES, they cant just assume that we know this shit
Thank you for this video.. I understand everything. Our professor's so fast in discussing these. Do you have videos like looking for the value of x using this? :)
@endauthority nothing is perfect. but i would say there are more educational opportunities for people than there ever has been in history, so it is probably not all that bad
Just like that top comment says, I see no reason to go to class. My lecturer is terrible and I come back to my dorm confused. Then I start studying here and I understand everything.
@yeahhyeahh ads are why you get to watch this stuff for free. baby jesus does not pay for this stuff you know. there are plenty of websites where you can pay a subscription and never have to watch an ad if that is what you prefer.
@atlboy72 well, i suppose it depends on what exactly you are looking for. i am not sure off the top of my head, but if you google 'cheat sheets calculus 2 ' or something like that, you can probably find what you are looking for.
THANK YOU SO MUCH. I take my notes in class very detailed but I still don't understand the concepts 100%. This is like part 2 of my notes and I'm definitely subscribing to you. Thank you and youtube lol
so we'll have e to the stuff times the derivative of the stuff. LMBO if you taught my calc class i would gladly go 2 class cuz my russian prof confuses me :( Your videos are alot of help.
@Skyrodude I would have to disagree. Sal Khan gives excellent lectures on both Math and Science areas (and plenty more), but I feel like both patrictJMT and Khan Academy are essential combinations for math success. When I go to these videos, I see interesting things, especially the way each of them approach problems. This is how I get a much more diverse tool chest, I get plenty more tools to choose from. Never ever restrict yourself to one source! Thank you Patrick for this Math Gold Mine here!
@Skyrodude Not true. Khan definitely goes into Physics, Chemistry and other sciences of course, but he teaches math as good as anyone else.
The difference with Khan and PatrickJMT is that Khan teaches math more intuitively, so you understand WHY you're doing what you're doing. Where as PatrickJMT teaches you how to attack the problems you're likely going to deal with on tests and problems. One's more intuitive, one's more mechanical.
Now watch them both, and you'll become a Super Saiyan.
Is it just my computer, or is the volume really low on this vid? I'm having a hard time hearing the audio, and I've got my sound at max volume. Regardless, thanks for your math vids, they're really helping me in my college algebra class!
I have a question (also test is tomorrow so answer right away would be great) i need to evaluate this: (16 / 9) ^ (2 / 3) ( ^ means exponent) the answer is 64 / 27 but i have no idea how to get there :(
YOU ARE AWESOME! Thank you for everything. btw, im a bit confused. whats the derivative of x-e^-x? Is it just 1-e^-x or it is something more complicated. thanks again!
@vplof x^(x^x) is kinda crazy. It would help to know the derivitive of x^x first. All you have to do is take the ln of x^x^x=y to get (using the log rules) (x^x)ln(x)=ln(y). then it just becomes an overly convoluted implicit differentiation problem, just take d/dx of bothe side the equation and solve for dy/dx. Hope this helps!
I think both of you guys are awesome. If i watch both khan academy and your videos on a topic, i seem to have a much better grasp of the concept than if i only listened to one. Plus more examples!
@patrickJMT your a great teacher but i think the reason he's becoming international is because he is not just focused on math he does other subjects and he is set on expanding. I think the way you explain it is formulaic based which to me is better but for people who struggle in Math they like the intuition he gives and the proofs to answer the question "Why the hell do I need this?" Moreover, he is very informal which is comforting for those who see this as Greek. (pun intended :P)
patrick, i love you and i want you to be my teacher. marry me and u can teach me math and we can have babies and well live happily ever after until im done with high school
You're so awesome!!! I'm soooo ready for this part of the test now, thanks for make it soooooo easy and breaking it up into basic parts! I love all your videos, thanks for helping us all out, you're definitely saving some academic lives:)
@patrickJMT hey man, your good at explaining, you should become a math teacher, BUUUT ne ways,i have a question, for my math hw "complete the statement: the gradient function of y=5^x is always......... than the original function." any ideas?
thx alot, my exam in a couple hour , and i couln't figure it out by looking at the book, they use the same equation but sum how way more confusing then the way you show in your vid.
For a f(x)= e^-x/(1+e^-x)2, what is equation of tangent line?
TheSahar58 1 week ago
Patrick im back at college and im in Calc II, I got an A in Calc I in part thanks to you, I hope I can repeat the miracle again :)
danlinkgan 2 weeks ago
@danlinkgan study hard : )
patrickJMT 2 weeks ago
what would you do if you have a^ln(2x) ??????
sharmoota120 1 month ago
pie times tea sounds delicious :-)
azerty1till9 1 month ago 4
Thanks!
iverson92123 1 month ago
what would y=e^-3x be?
nxnaruto 1 month ago
@nxnaruto -3e^-3x
supahhflychicken 1 month ago
I'm pretty sure I could answer most of the examples after watching you work it out a few minutes. Then I look at my homework and it doesn't even look similar
letha11egacy 1 month ago
OMG I DONT EVEN NEED TO GO TO CLASS I CAN LEARN THIS SH"T IN 5 MINS WITH YOU :D
ComputerNerd666 2 months ago
Hey, what's something like x^x?
sokkerking12345 2 months ago
@sokkerking12345 that is not an exponential function. you have to use logarithmic differentiation to find the derivative
patrickJMT 2 months ago
My math book attempts to explain all of this in just two lines, complicated as hell. You, sir, alleviated my confusion. Thx!
PwnagePC 2 months ago
how about f'(x) of the function: ln[ln(4x^2*sin^2x)]
thank you for the video!!
BostonGreen17 2 months ago
I dont understand a thing...
altairvrak 2 months ago
@altairvrak
Well, then you're screwed because this is really as understandable as it's gonna get!
pch34O 2 months ago
Comment removed
SayianArtist17 2 months ago
I love your use of the word "stuff". Such an underrated word.
mcovalt 2 months ago
This is genius!!!
titus120 2 months ago
Where can I find an example of how to find the derivative of x to the power of x only a whole lot harder?
katerinawsy 2 months ago
reallllly u are awsome .. i love u alot :)))
guliseflower 2 months ago
Thanks for all the vids. You've helped me to understand every inch of this subject, something my teacher has so far failed to do. In turn you've helped me earn a GPA which has rewarded me with full tuition to any school I want :) Great job!
Altare1994 3 months ago 10
@Altare1994 ha, sounds like you owe me a nice donation! : )
patrickJMT 3 months ago 32
can someone reply to me what an "e" stands for like can it be any number or is it a certain type of number please reply i
danyhighmonster 3 months ago
@danyhighmonster In official mathematical lingo, e is Euler's number so I would assume in this video it is Euler's number. e = 2.71 roughly. The base of the Napierian logs.
VIR092 3 months ago
e is a constant and it's value is 2.71.
it's a certain type of constant, u can't write anything else in it's place
lakshitaa1 2 months ago
Thank you for the video.
grandmasternmk 3 months ago
@grandmasternmk you are very welcome
patrickJMT 3 months ago
more harder examples?
suenge 3 months ago
Nice Job!
sghayder 3 months ago
Patrick, can you take derivatives of functions involving absolute values?
lisinka3 3 months ago
thank you for explaining the FULL equation. i was wondering why in the book and in the lecture that when the powers got more complicated that just x, that they tacked on some random shit. Why the hell would they shorten the equation? i think the WHOLE fucking equation is important AT ALL TIMES, they cant just assume that we know this shit
Kickasss119 3 months ago
@Kickasss119: Wow, your comment sure is kick asss. :-B
@patrickJMT: Thanks for your videos. :-)
Pretoriafly 3 months ago
Thank you for this video.. I understand everything. Our professor's so fast in discussing these. Do you have videos like looking for the value of x using this? :)
JdunnoMEE 3 months ago
I love you..."some complicated stuff" priceless
DarkDraven7 3 months ago
i am dropping out school now, like seriously youtube have everything i need to learn about math, physics, and etc
5StepsBack 3 months ago 5
@5StepsBack the internet is changing education, that is for sure!
patrickJMT 3 months ago 3
@patrickJMT its too bad that one cant get credit for learning, but rather time spent in a flawed educational system
endauthority 3 months ago
@endauthority nothing is perfect. but i would say there are more educational opportunities for people than there ever has been in history, so it is probably not all that bad
patrickJMT 2 months ago
my 45 minute calc class summed up in 5 minutes.
THANK YOU
YOU ARE A GOD SEND
justlikemia3 3 months ago
OH MY GOD YOUR HANDWRITING IS AMAZING
ProfessorRaichu 3 months ago
Just like that top comment says, I see no reason to go to class. My lecturer is terrible and I come back to my dorm confused. Then I start studying here and I understand everything.
DarthMrB 4 months ago
@DarthMrB glad my videos help at least : )
patrickJMT 4 months ago
man when calc II is all said and done i will have memorized (what seems like) a million formulas/rules/propeties/identities
TheNumber2Pencil546 4 months ago
ty
pepteamsergi09 4 months ago
patricia i love you.
toxictits 4 months ago
@toxictits my feminine alter ego thanks you
patrickJMT 4 months ago 5
Thank you! Really short and to the point on essentially all the types of problems I will encounter in the section of calculus I'm covering right now
gregbielak 4 months ago
those adds are so annoying ..one is trying to do their hw and theyre just so distracting ugh
yeahhyeahh 4 months ago
@yeahhyeahh ads are why you get to watch this stuff for free. baby jesus does not pay for this stuff you know. there are plenty of websites where you can pay a subscription and never have to watch an ad if that is what you prefer.
patrickJMT 4 months ago 5
Do you know where I can get a good sheet with all the formulas on it from calculus 2?
atlboy72 5 months ago
@atlboy72 well, i suppose it depends on what exactly you are looking for. i am not sure off the top of my head, but if you google 'cheat sheets calculus 2 ' or something like that, you can probably find what you are looking for.
patrickJMT 5 months ago
thank you :")
Ishi1XP 5 months ago
how about e raise to negative x?
charlesbene 5 months ago
you should raise your voice a bit !!
mamu7mich 5 months ago
What if it's f(x)^x or f(x)^g(x)?
buhoman3 6 months ago
patrickJMT: "I'm so smart I do my math in permanent marker"
Me: "If only..."
xlph 6 months ago 3
this guys voice just makes calc so much easier
hmlsport 7 months ago
Patrick, I'm assuming you have taken physics and most likely did exceptionally well. Therefore, you should start making some physics videos as well!
Jfrancis221 7 months ago
I dont understand, in the proof of why y=a^x when differentiated is a^x x lna
because: take logs of both sides lny = xlna
then differentiate : 1/y x dy/dx = d/dx (xlna) < on this bit how do they differentiate to just lna????
sophieroseplatts 7 months ago
grt wrk...wil hlp m n exam
Muzanywa 7 months ago
grt wrk...wil hlp m n exam
Muzanywa 7 months ago
awesome videos! Thanks
ian559fresno 8 months ago
every video i see of yours, i get mind fucked....my teacher sucks ass :p
rickyrubio94 8 months ago
:( you didn't simplify
309401164 8 months ago
thank God you're left-handed.
hashmat187 9 months ago 6
Just realized my lecturer is a retard... no actually i think iv known all along.
Morgam06 9 months ago
nice job, you skip ahead a little, but straightforward and good examples....thanks
dingdingdavid 9 months ago
THANK YOU SO MUCH. I take my notes in class very detailed but I still don't understand the concepts 100%. This is like part 2 of my notes and I'm definitely subscribing to you. Thank you and youtube lol
alen132465 9 months ago
where exactly is the bunch of other videos?
jackxzx 10 months ago
Your videos are awesome and insanely helpful
dwarven444 10 months ago
Oh my gosh.
I spent 30 minutes trying to teach myself this lesson in my textbook.
I understood it in five minutes, all thanks to you.
You.are.amazing.
AnimangaArtist 10 months ago
so we'll have e to the stuff times the derivative of the stuff. LMBO if you taught my calc class i would gladly go 2 class cuz my russian prof confuses me :( Your videos are alot of help.
toda9008 10 months ago
I wish I had found your channel 6 months ago...Your channel is better than all 3 of my different calc teachers on their best days. Rock on dude.
MisterJesse 10 months ago
with love, from Malaysia. <3
struggling in Australia hahahahaha
98hahelos 10 months ago
why dont you have algebra videos? :(
98hahelos 10 months ago
Comment removed
hockeyism1 11 months ago
i dont even go to class any more i just watch your videos
zhaze420 11 months ago 45
@zhaze420 ha, go to class
patrickJMT 11 months ago 60
@patrickJMT NO
zhaze420 11 months ago
@patrickJMT
Maths class at 6:30 in the morning does not lend itself to good attendance.
wantontrollop 8 months ago
khanacademy = for physics.
patrickjmt = math.
Skyrodude 11 months ago 21
@Skyrodude that is what i want to hear (since all i do is math!) : )
patrickJMT 11 months ago 7
@Skyrodude spread the word
patrickJMT 11 months ago 8
@patrickJMT Patrick are you a genius at physics too? if you can post some of those it'll be awesome!
534coolio 9 months ago
@Skyrodude too bad physics is easy.... lol Calculus is a destructive Force
eclipse245 9 months ago
@Skyrodude I would have to disagree. Sal Khan gives excellent lectures on both Math and Science areas (and plenty more), but I feel like both patrictJMT and Khan Academy are essential combinations for math success. When I go to these videos, I see interesting things, especially the way each of them approach problems. This is how I get a much more diverse tool chest, I get plenty more tools to choose from. Never ever restrict yourself to one source! Thank you Patrick for this Math Gold Mine here!
NothingAtAllXD 8 months ago
@Skyrodude Not true. Khan definitely goes into Physics, Chemistry and other sciences of course, but he teaches math as good as anyone else.
The difference with Khan and PatrickJMT is that Khan teaches math more intuitively, so you understand WHY you're doing what you're doing. Where as PatrickJMT teaches you how to attack the problems you're likely going to deal with on tests and problems. One's more intuitive, one's more mechanical.
Now watch them both, and you'll become a Super Saiyan.
TheHypaLink 5 months ago 5
Is it just my computer, or is the volume really low on this vid? I'm having a hard time hearing the audio, and I've got my sound at max volume. Regardless, thanks for your math vids, they're really helping me in my college algebra class!
cabolisa 11 months ago
@cabolisa It must just be your computer, I can hear him fine at 34% volume. Try using headphones instead of speakers if your speakers aren't good.
mmykle 11 months ago
can you explain why the derivative of f(x)=e^x is f'(x)=e^x please.
im still confused :S
curlyhair1993 1 year ago
Thanks! Great video!
jenbrenner 1 year ago
a better wording for the derivative of e^x would be e^x * x' ... that's because if x were 2x, then the derivative would be e^x * 2
scbaldwin13 1 year ago
thank u very much شكراً جزيلا
Kingboy676 1 year ago
BYU loves YOU!
ILOVEGIRLS808 1 year ago
I have a question (also test is tomorrow so answer right away would be great) i need to evaluate this: (16 / 9) ^ (2 / 3) ( ^ means exponent) the answer is 64 / 27 but i have no idea how to get there :(
TsukiLune 1 year ago
@Resi2birkin does the order matter?
patrickJMT 1 year ago 4
Comment removed
xxProjectRebirthxx 1 year ago
@Resi2birkin yep
patrickJMT 1 year ago
University of Waterloo loves you!
I am sooooo not worried about my calculus midterm tomorrow anymore!
firenuts1800 1 year ago
YOU ARE AWESOME! Thank you for everything. btw, im a bit confused. whats the derivative of x-e^-x? Is it just 1-e^-x or it is something more complicated. thanks again!
gengen23100 1 year ago
Wow your are the best teacher ever, thank you so much.!!!!!!!
What about x^x^x dont know how to
vplof 1 year ago
@vplof x^(x^x) is kinda crazy. It would help to know the derivitive of x^x first. All you have to do is take the ln of x^x^x=y to get (using the log rules) (x^x)ln(x)=ln(y). then it just becomes an overly convoluted implicit differentiation problem, just take d/dx of bothe side the equation and solve for dy/dx. Hope this helps!
tatfr0guy 1 year ago
Thanks!!!! From University of Puerto Rico :)
TheMolo4712 1 year ago
Patrick, I love you.
AbstractRS 1 year ago
can i borrow your brain for my test tomorrow?
DMoyer91 1 year ago 2
wow dude i seriously don't need to study for my math test tomorrow. Thank you very much
StoN220 1 year ago
I should sue you for making me slap my forehead so much all the time! :D
Romeowasbleeding1 1 year ago
bro, i love you..no homo
iniloy1993 1 year ago
He's left handed...what do you expect?
vidoecommenter1 1 year ago
Thank you! You might just help me pass Calculus II. GA Tech Calculus has totally kicked my butt.
thestateofdecay 1 year ago
Kahn Academy couldnt wipe your but PatrickJMT!
also, he has terrible handwriting!
abombinreverse 1 year ago
@abombinreverse ha, well, he is doing good stuff too for sure : ) glad you like my stuff though!
patrickJMT 1 year ago 6
@patrickJMT I do like ur math better than his, no doubt he is a smart dude
ny1fanta 1 year ago
@patrickJMT
I think both of you guys are awesome. If i watch both khan academy and your videos on a topic, i seem to have a much better grasp of the concept than if i only listened to one. Plus more examples!
MattyHild 1 year ago
@patrickJMT i laughed at this comment, ITS MATH WARS!!!
skrevat 1 year ago
@abombinreverse Yoooo!!
Chilll mann!!!! I am a fan of both guys!
MistaFranko 1 year ago
You and Khan Academy are superior expositors. Both of you cut the slack on college stress. Keep up the good work.
EdMahoney19 1 year ago 2
@EdMahoney19 glad you like us both : ) khan seems to be taking over the world while i quietly go about my business!
patrickJMT 1 year ago 3
@patrickJMT your a great teacher but i think the reason he's becoming international is because he is not just focused on math he does other subjects and he is set on expanding. I think the way you explain it is formulaic based which to me is better but for people who struggle in Math they like the intuition he gives and the proofs to answer the question "Why the hell do I need this?" Moreover, he is very informal which is comforting for those who see this as Greek. (pun intended :P)
natdogrocker 1 year ago
I think maybe adding some proofs for some of the concepts would be nice, but other than that good show mate.
QuakinginFEAR 1 year ago
ur teaching style is very straight forward and very easy to understand. i like that. are u teaching at a university?
adoboholic 1 year ago
This method doesn't work for finding the derivative of x^x
mishiiee 1 year ago
watching youtube is always the best way to study for a text!
like9orphanz 1 year ago
my hope has been renewed thanks to your video. Thank you Patrick.
Volcin 1 year ago
Thanks for making these vids! They're truly helpful~(:-
mypinkdollprincess 1 year ago
I love you... The problem I need help on for my high school calculus final tomorrow is the first one you cover.
royce97 1 year ago
i appreciate the videos and their varied difficulties. they are the only reason i have any idea about what is going on in my calc. course.
thank you for posting these. really.
erisontop 1 year ago
this video is really helpful. thank you
i have a question, i dont know how to get the derivative of h(z)= z^2(1+e^-z)
gengen23100 1 year ago
nice
elten400 1 year ago
Isn't the last example with cos the product rule?
Nargaz 1 year ago
@Nargaz no, it's the chain rule because there's only one term. the 2^πt is the angle for cos, making it one term.
neonsmileee 1 year ago
awsome! Gosh I was so lost in my lecture. and I saw your vid and Voila! Thanks!
airfreak789854521 1 year ago
patrick, i love you and i want you to be my teacher. marry me and u can teach me math and we can have babies and well live happily ever after until im done with high school
whooperpooper86 1 year ago
can u plz explain the last problem again ?
i didnt understand how u took the derivative of whats inside the brackets
MsEmm22 1 year ago
So great! Thanks so much!
OARHEGOS 1 year ago
omg so helpful!!!!!!!!!! thanks =)
ily8992 1 year ago 2
you should be my Calculus teacher!!!
sfcolombia 1 year ago 4
pretty good lecture nice job
MrKwanlee 1 year ago 3
Once again, easily explained here than in class or in the book.
xilllllix 1 year ago 8
he's a number ninja
username14657 1 year ago 3
You're so awesome!!! I'm soooo ready for this part of the test now, thanks for make it soooooo easy and breaking it up into basic parts! I love all your videos, thanks for helping us all out, you're definitely saving some academic lives:)
sm3116332 2 years ago 5
Thank you man. You are just fantastic and funtastic to...
crazyanton1953 2 years ago 4
This guy must have the biggest package.
karlkarlkarl1234 2 years ago 12
THANK YOU! this really helped. keep it up, your method is really helpful :)
babiappl333 2 years ago 2
Thanks for the explanations, they are much appreciated!
amjPeace 2 years ago
you are jesus in math form, your beard is comprised of heavenly math equations and your halo of awesome explanation
TheBitchesNCream 2 years ago 71
@TheBitchesNCream LOL!
Skizzorhands 11 months ago
wow, lots of "stuff"
sweet16girl657 2 years ago 2
thank you man youre the best.
manny95020 2 years ago 3
u are my hero
XxTNTxX92 2 years ago 4
Does anyone know where I can get info of how to graph the integral of f ' (x) when the graph of f ' (x) is given?
godzac 2 years ago
HAHA, I love how you call the function in the exponent "stuff". To the derivative of that "stuff". idk, it's just funny to me lol
miinibee 2 years ago 6
This has been flagged as spam show
STFU
xxxNubCakexxx 2 years ago
thank you so much for posting these videos, they really do help alot.
DatATLGurl770 2 years ago 3
hey do u have a vid abt integration using exponential functions?
rEdsNip 2 years ago
The way my textbook tried to explain this made no sense at all...but the way you explain it makes sense. Thank you so much!
hangloose1350 2 years ago 2
i have a problem, e^cosx+lnx
would that just be e^cosx+lnx by (-sinx + 1/x)
smcwilly08 2 years ago
i like your teaching style.... the last problem is tough though....
ge4r1a5ldsayz 2 years ago
if i make them all easy, people yell at me : )
patrickJMT 2 years ago 2
why are you so smart?
macNdow 2 years ago 7
10% smart
90% willing to work my ass off
patrickJMT 2 years ago 83
@patrickJMT I love that quote. Seriously.
I love what you're doing on here, you're single (and left) handedly saving so many kids, including myself.
I can't thank you enough, honestly. You've helped us all more than you could ever imagine. May I ask what you do for a living/studying in school?
TheDatsunKing 1 year ago
@patrickJMT hey man, your good at explaining, you should become a math teacher, BUUUT ne ways,i have a question, for my math hw "complete the statement: the gradient function of y=5^x is always......... than the original function." any ideas?
brosbeenrandom 1 year ago
@patrickJMT i like your willing to work vs smart ratio but i believe you have it backwards lol
walkerwiggins0 10 months ago
e to the stuff times the derivative of that stuff...he he he...sweet!!
But no doubt, an excellent video!!
aztips 2 years ago 2
do you have any videos on applications?
1a1a2a3a 2 years ago
you speak in a language i can understand :D . thank you!!!!
RThrisala 2 years ago 2
you would have to distribute the e^x, yes, if that is what you are asking
patrickJMT 2 years ago
Hey, is it possible to intergrate e^f(x) dx? I've been trying to integrate e^(x^2) but it only seems possible to approximate using Taylor series :?
braskasguardian 2 years ago
you can not integrate e^(x^2) in terms of elementary antiderivatives.
u are correct : we use taylor series to approximate
patrickJMT 2 years ago
ok, thanks!
braskasguardian 2 years ago
Thanks, this really helped a lot! I wish all math was taught like this.
scottturner1994 2 years ago
I think I'll stick with physics :)
captaineothan 2 years ago
Love you usage of the phrase "complicated stuff".
dirtydeeds2447 2 years ago
What if you have something like:
X^(2x)
svfan 3 years ago
then you use logarithmic differentiation...
fortunately, i have a few videos on that!
patrickJMT 3 years ago
thx alot, my exam in a couple hour , and i couln't figure it out by looking at the book, they use the same equation but sum how way more confusing then the way you show in your vid.
Longmachao 3 years ago
glad it helped
patrickJMT 3 years ago
can i you solve this please..i cant understand this equation..
sec²(1-e^ -x)
please..i'll wait for the answer..
thank you..
ixhapein 2 years ago