Question

f(x) = ax^3+bx^2+cx+d

find a,b,c,d so that the function has a local maximum at f(-1) = 2 and has a local minimum at f(1) = -1 HARDEST QUESTION EVER I CAN NOT FIGURE THIS OUT!!! PlZ I NEED THE BEST OF THE BEST

Answer 1

And I tell u this the simplest of all I have ever seen.

Answer 2

Really?!

Answer 3

I think i just don't know what it's asking

Answer 4

Ok here is how u solve it
f(-1) = 2 =-a+b-c+d
f(1) = -1 = a+b+c+d
And since the above two points are local minimum and maximums, this must hold true
f'(-1) = 0 and f'(1) = 0
But f'(x) = 3ax^2+2bx+c
Thus
f'(-1) = 0=3a-2b+c
f'(1) = 0 = 3a+2b+c
Now you have four equations with four variable.
Will u finish from this?

Answer 5

oh yes, thank you

Answer 6

your a genious

Answer 7

you deserve a metal