Question

The function F(x)=e^(-7x^2) has two inflection points. Find the x- coordinate of the inflection point when x>0, correct to two decimals.

Answer 1

\[f'=(-7x^2)'e^{-7x^2}\]
\[f''=([-7x^2]')'e^{-7x^2}+(-7x^2)'(-7x^2)e^{-7x^2}\]

Answer 2

Okay, and how do I go on from there? Multiply it out..?

Answer 3

find when f'' is 0

Answer 4

I got \[1/\sqrt{7}\] but it says that's not right...

Answer 5

Got it, should've been a 14 instead of a 7

Answer 6

i left out a prime up there
oh well you got it
gj