Question

f(x)=(x-1)(x^2+2)^3, find f'(x)

Answer 1

@electrokid

Answer 2

I used product rule but my answer isn't one of the multiple choice options :S

Answer 3

@agent0smith

Answer 4

show your steps using the equation editor.

Answer 5

you have to use product rule and chain rule

Answer 6

yeah i did that and i got

Answer 7

\[(x-1)(x^2+2)^3 \times 2x + (x^2+2)^3 \times 1\]

Answer 8

ok, lets split this:
\[
u=x-1\implies u'=1\\
v=(x^2+2)^3\implies v'=3(x^2+3)^2(2x)\\
f(x)=uv\\
f'(x)=u'v+uv'
\]

Answer 9

correction..
\[
u=x-1\implies u'=1\\
v=(x^2+2)^3\implies v'=3(x^2+\color{red}2)^2(2x)\\
f(x)=uv\\
f'(x)=u'v+uv'
\]

Answer 10

see what you missed there?

Answer 11

your derivative of "v" was incorrect

Answer 12

ohhh

Answer 13

ty :)

Answer 14

yw