which means that he ends up with -79 square rooted, and unless using imaginary numbers then negative square roots are not possible, another is that it's 100 seconds, but i salute your attempts and the working out would be fine, just a bad equation, and quadratics aren't and shouldn't always be solved with this method
I have to give the guy credit for one thing. I'm a teacher and a lot of my students have the attention span of a gnat and the 60 sec format is great for that. Still, it would have been just as easy to make a 60 sec lesson using an actual equation with an equal sign and also use an equation that has real roots instead of imaginary roots.
He probably just misread his 15 as a 10. And yeah, he didn't show a legal "equation" at all. I'm sure if he did he could have explained why you'd zero the y, what you're really solving for/why, maybe point to a graph... just those little things that make Math relevant instead of confusing... who needs 'em? :P
1. the 'expression' cannot be solved because there is no equals sign in the expression
(it should be: 3x^2-11x+15=0)
2. You haven't shown how to substitute a, b, c. The quadratic could be written in a different order.(say: -11x+15+3x^2=0)In this case, a is not the first coefficient, and b is not the second (like you said) etc.
3. 4*3*15 is not 120 - it's actually 180
4. This leaves you with -60, which cannot be square rooted
2. To clarify, a, b, and c can only be identified when the quadratic is in STANDARD FORM ax^2 + bx + c = 0.
3-5. ?? You can "check" the solutions with synthetic division or by FACTORING, which obviously won't work (no factor pair of ac = 45 has sum of +/- 11).
'an error occurred. please try again later' fuck, nooo! i need this for exams tmr!
sillystringgs 4 months ago
Hey this is 1:40! Kinda off from :60 :(
But good job anyway :)
SuperCrazyAngela 1 year ago
fuck no! 4(3)(15) = 180!!!!!!!!!!!! WTF?
SKAD4LIFE86 2 years ago
He can't use the formula. How does he know that the original equation was equal to 0. It doesn't say so.
Ah ha, I've found the flaw
NotJames1 2 years ago
no that is one of the floors, another is that on the fourth line he has 121-120, he states 4 x 3 x 15 is 120
robdurant22 2 years ago
which means that he ends up with -79 square rooted, and unless using imaginary numbers then negative square roots are not possible, another is that it's 100 seconds, but i salute your attempts and the working out would be fine, just a bad equation, and quadratics aren't and shouldn't always be solved with this method
robdurant22 2 years ago
floors??? LOL
Blobsterisation 2 years ago
Haha Yeahh, well it was my friend who's really into maths, so he used my account to rant.... :L
robdurant22 2 years ago
Does this method work? because i got like twenty of them to solve for my home work and dont understand.
MrUllysees 2 years ago
Yeh this works alright.
Worshipthegodof 2 years ago
Comment removed
porkchop00000 2 years ago
Can anyone tell me how you use quadratics in the real world with an example please.
iceman341h 3 years ago 2
we dont. the educational system of the modern world is just flaued
varun009 3 years ago
I can see it was flawed for you... You cannot even spell flawed right.
parkourjordz 2 years ago
slip of the finger
varun009 2 years ago
Yea I was just joking :)
parkourjordz 2 years ago
Do a youtube search on numericalmethodsguy quadratic equation example
numericalmethodsguy 2 years ago
So what if he messed up. That's not what math or these videos are about.
k2jroche 3 years ago
I have to give the guy credit for one thing. I'm a teacher and a lot of my students have the attention span of a gnat and the 60 sec format is great for that. Still, it would have been just as easy to make a 60 sec lesson using an actual equation with an equal sign and also use an equation that has real roots instead of imaginary roots.
gdawgrapper 3 years ago
Wow, someone that's barely smarter than Obama....
powerblip 3 years ago
He probably just misread his 15 as a 10. And yeah, he didn't show a legal "equation" at all. I'm sure if he did he could have explained why you'd zero the y, what you're really solving for/why, maybe point to a graph... just those little things that make Math relevant instead of confusing... who needs 'em? :P
Swin0 3 years ago
You should change your name to Maths crappy tutoring. people like you should be learning ....not teaching
markcommo123 3 years ago
you are right bro ppl like this guy should be tutoring him self MARKCOMMO123
grig24x 2 years ago
ARE YOU RIGHT OR WRONG???
makkaulahsial 3 years ago
If you just state that 3x^2-11x+15 you simply have NO equation!
x+2=0 or x^3+x=4 are equations....
xjuhox 3 years ago
you have a lot of errors mate
1. the 'expression' cannot be solved because there is no equals sign in the expression
(it should be: 3x^2-11x+15=0)
2. You haven't shown how to substitute a, b, c. The quadratic could be written in a different order.(say: -11x+15+3x^2=0)In this case, a is not the first coefficient, and b is not the second (like you said) etc.
3. 4*3*15 is not 120 - it's actually 180
4. This leaves you with -60, which cannot be square rooted
5. there are no solutions here.
PAUPERSTAR 3 years ago
1. Right on
2. To clarify, a, b, and c can only be identified when the quadratic is in STANDARD FORM ax^2 + bx + c = 0.
3-5. ?? You can "check" the solutions with synthetic division or by FACTORING, which obviously won't work (no factor pair of ac = 45 has sum of +/- 11).
Consider this a peer review
888Xristos 3 years ago
4ac is 180, so you will get irrational number...
filla1776 4 years ago
dude.
i've calculated this like, 8 times, its -180.
dontcareanymor 4 years ago
You've made a mistake. It should be sqrt(121-180). Since you can't calculate square root of a negative number there are actually no xs to calculate.
TomIRIDIUM 4 years ago
can you tell me what grade this is taught in please? thanks....
airpizza 4 years ago
about 8th or ninth
DvD175 3 years ago
dude where did you get 120 from?
driftix 4 years ago
it should be -180
usmacadet2013 4 years ago
cool. thanks for explaining that
Ari01 4 years ago
Yes, anytime they leave out a "part" (an x^2, an x, or a number) that means there's zero of them, so you can place a zero there if you like.
MathCrazyTutoring 4 years ago
excuse me if there is no c duz that mean its zero?
OhEmGeeitszHend 4 years ago