Inverse Trig Functions: Arcsin

[kurankaname111]

14 year old guy that studies physics trigonometry chemistry geometry but not good in math..,, T_T we just need to study it because of my high section in school

[DjDrfreeman]

Magnets motherfucker, TEACH ME HOW THEY WORK

[schrammscythe]

5:35 . thought he made a face... nope, chuck testa.

[hhira13]

@schrammscythe reddit.....

[aboyandhisuke93]

I used to be good at math, than i took an arrow in the knee...

[hhira13]

@aboyandhisuke93 reddit......

[Smoothknight]

i got sea sick watching the cursor.. :s

[JohnBarchard]

I just figured out how to make my boat for Physics!

[alobar1234]

please tell me where you got that ti-85 program!!!!

[alobar1234]

found it!! ticalc9(dot) org/ soooo awesome

[pokeseye]

I like how I know the answers already.

[369katdogg]

Mind=Blown



[MusicholicV]

wait why dont you need to round the 1.04 to 1.05 since the next digit is 7?

[ian559fresno]

Thanks

[urababoon13]

it's not equal to 1.04 its approximately 1.04 lol false advertisement bud

[EaglesFastAndLow]

This is absolutely amazing.

[sarablack10]

Thank you very much!

[zq1811]

THANK YOU THANK YOU THANK YOU. Hopefully im no longer failing my calculus course. THANK YOU!!

[randomsmack12]

-_- im sooo lost...

[PaliMatic]

@2:18 he was going to say "But this is some new... some new shit i've never seen before"

[PBxTHExNIKExSBxOGx]

alg. II (adv) final tomorrow. THANKYOU!

[FredrichNietzsche25]

Hey sal, is it possible to have a graph of arcsin? And, if it is could you do a video on that?

[GoldFish705]

My school's pre-calc teacher has had family emergencies this past month, and hasnt been in once. She wanted us to learn how to do all of this ourselves, bc the sub couldnt really teach it. I seriously knew nothing until i saw your videos.. and now i actually understand stuff. Finals are in 2 days. I LOVE YOU

[kurozaki45]

how do you use a triangle to solve this problem?

tan(sec^-1(x))

[qsierra1]

Isn't the hypotenuse of a 45, 45, 90 triangle the square root of 2?

[OlofTheBald]

@qsierra1 Hypotenuse can be any positive number, the angles won't change.

Sal simply said it was 1 because he is assuming the unit circle's radius is 1 for simplicity.

[1piecemage]

this part is simple, its pure memorzaton...

can you give steps on solving identity?

[evolutionofvanity]

I ENVY YOUR BRAIN!!!!! btw YOUR videos ar "A" "may" "zing" Best math/physics teacher ever thanks for providing an incredibl epublic service, you have made my pathway to an engineering degree way easier!!! :)

[cvin519]

What software do you use? Me gusta

[puzzlepeace19]

Why do you restrict it to the first and fourth quadrants?

[thenewguy461]

@puzzlepeace19 because the function of Arcsin has a domain of pi/2 and -pi/2. If it was unrestricted then it would be a relation and not a function.

[brownsugarchic]

@puzzlepeace19 because SINE's restricted domain is QI and QIV, same as the TANGENT, while COSINE's restricted domain is QI and QII.

[puzzlepeace19]

Why do you restrict it to the 1st and 4th quadrant?

[loveandance]

THANK YOU!!!!!! Ahhhh you are a life saver!

[jgolob92]

You are the most useful person on youtube.

[DangerMac123]

Tyvm for the video, really helped me alot!

[melodyofafrenchy]

Sal, quick question - when you're solving and it asks the arcsin of some crazy number (say, sin^-1(4/5)) how do you get an angle value if you're not allowed to use a calculator? I can get each leg of the triangle, but unless I have a calculator, there's really no way to figure out the angle in degrees OR radians

[SKINNY15lol]

you dont have to draw a stupid triangle to solve this equation, for sin and cos all you have to do is memorize the unit circle and you automatically know...your making it so complicated when it doesnnt need ot be

[falcodarkzz]

@SKINNY15lol

The words of a poor mathematician. Sal is showing WHY, a far more useful way of solving problems than simply churning information memorised by wrote.

[BobbySKeight]

thanks so mch i wish you could be my teacher

[barimaster13]

@Heforeverlives I know what you are saying, I always learned 45-45-90 triangles as 1-1-squareroot of 2. It is simply a different way of doing it, but it is the same math.

[Rcberry9]

@Ajmasterb12 That is why he is such a good teacher. Any teacher can teach you a shortcut, but not every teacher can break it all the way down to the proof.

[TheRealTingAling]

i can't believe my school made me buy epgy to skip math, it was 750 bucks, and their videos were complete crap compared to yours

[Ajmasterb12]

:00-1:40 he did all that work just to get square root of 2 over 2? It took me 2 secounds to look on my unit circle to figure that out!

[ericloyd82]

Very helpful. More Please. Thanks

[HeForeverLives]

Since when is a 45-45-90 triangle's hypotenuse=1???

[AwayWeGLOW]

@HeForeverLives When its on the unit circle. It's radius is always 1.

[semsudin911]

@HeForeverLives circle diameter is 1 -.-'

[melodyofafrenchy]

@HeForeverLives i'm assuming you learned that in a 45-45-90 triangle the legs are "x" and the hypoteneuse is "x times the square root of 2". (or 1, 1, and 1*root2).

Well basically, a unit circle always has a radius of 1. So if 1 is the hypoteneuse, the legs are Squareroot(2)/2 each. You can see that more easily backwards - if the a leg is Square root of 2 divided by 2 and the hypoteneuse is root(2) times this, you'll get root(2)/2 * root(2) which is 2/2 which is equal to 1. Hope this helps!

[st335533]

If a stranger came to me and asked me what the sin of pie/4 or the arcsin of (sqrt2)/2 is id answer his problems by giving him the directions to the nearest psychiatric ward

[st335533]

@st335533 that or i'd beat him with a purse, which the crazy part is, im a man, and dont own a purse O,o

[Artyompyandex]

Hey, thank you for this video... however i have a misunderstanding: When (i.e) sin(x)=-(sqrt2)/2, couldn't x be (5pi/4), (7pi/4), and (-pi/4)? Thank you for help :)

[callitasisee]

@Artyompyandex Actually, the question would be arcsin(x)= (sqrt2)/2. This is because you are trying to find the radians. And, no, every answer there besides (-pi/4) would be incorrect. This is ok, but you have to remember that you only deal with the 1st and 4th Quadrant with arcsin. the range for both arcsin and arc tan are between (-pi/2) and (pi/2). Your other answers are not within the range. I hope I could help you :)

[ajmendoza1]

what program are you using? like the little chalkboard thing.

[DinoRiott]

You just saved my math grade!!!! Thankyouthankyouthankyou:)

[xcstacy2]

I love you, I love your videos, I love your voice, I love the help you give people like me :D My prof in my first year calculus course has such a thick accent I can't understand him so I have to basically teach myself this stuff but when I get stumped you are my saviour!

[arsekik]

Hey Sal,You are=sin^a+cos^a=1

.

sin^2(awesome)+cos^2(awesome)=­number 1 !

[mbrents4]

what software do you use for these videos?

[homousios]

what sine are you?

[rajzep]

You are awesome. Thanks a lot.

[91jgphonecall]

who's walking up to you asking math queastion? anyway, if you get a number with a long decimal (1.732050808) on you calculator and you suspect its a square root of a number, push the square button to square it...Ans^2 =3, is how it looks on my calculator.

[CSRealist]

This is the point in my high school math studies I stalled. Good thing the GMAT doesn't get into this (too greatly...)

[ammarhollywood]

I love this guy , he saved me so many times

[Genivkuvo]

Your voice is awesome.

[grimwatcher]

Why do we need textbooks when we have Khanacademy?!

oh, yeah I forgot, to pay for overpriced books

[VivaLaVieRENT]

Marry me.

[yeunju7]

wow, i talked to my teacher for about 4 hours about this, and you explain all what i need in 5mins... i love you.

[lukoshke]

Thanks a lot man!

[WackoWasko]

Sal, you're amazing! Whenever I miss a day, you always have a video for whatever lesson I missed. Keep it up!

[anniemarieevans08]

Love your stuff! What software are you using?

[MrPiPPo]

you have the same calculator that i do.

[Swetlana0]

I think your handwriting changes with change in software!

[ABCba5tard]

@Swetlana0 he used paint software in his old videos O_o

[Swetlana0]

@ABCba5tard

Yeah but now his videos have far better quality than before!

I think we all can agree on that.

[roachey15]

@Swetlana0 I'd say it's just because he has a tablet now, so it's his actual hand writing, where as before he was using his mouse to write on paint.

[milkboionduty]

thank you!!! ur a life saver

[GlobalDuty]

Mashallah brother!

[garzers]

how come for arcsin ((root 2)/2) isnt considered in the 2nd quadrant and only in the 1st and 4th quadrant?

[soccerman1434]

Good question, arcsin(sqrt(2)/2) is defined in both the first and the second quadrant; it is also defined in multiple rotations around the circle. However Arcsin(sqrt(2)/2) [notice capitalization] is uniquely defined in quadrants 1 and 4. We restrict the Arcsin in these quadrants so that it remains a function.

[noblessus]

Hi! I just discovered your channel and your math videos are great!

Question; do you have a video where you talk about how to convert trigonometric expressions to algebraic expressions? I'm having trouble with that. Thanks!

[Hakeemn64]

Thank you!!!

[myaccc123]

Hey Sal. Can you do a presentation on integration involving trig inverse functions?

[Srxjer]

Nice new software. :D

[Nandine2]

OMG thank you so much sal, for responding to my request! And I understand it fully it now,

[chinkahbell]

more trig please!!

[lookwhoscomin]

Your handwriting was better now =)

What did you use?

[luistr01]

good :)