? asked in Science & MathematicsMathematics · 8 years ago

Difference between f'(g(x)) and (f o g)'(x)?

Given the following functions:

f(u)= (u)^1.5

g(x)= (x^4)+1

I found the (f o g)'(x) to be equal to: 1.5((x^4)+1)^.5 * 4x^3

I also need to find the f'(g(x)).... what is the difference between the two?

-Thanks

Update:

Zhou: Well I'm doing online homework and I copied and pasted the answer from the first to the second and it say it's wrong, though. :/

1 Answer

Relevance
  • Zhou
    Lv 5
    8 years ago
    Favorite Answer

    THere is no difference. They are the same.

    f(g(x)) = (f o g)(x)

    Therefore, their derivatives would also be the same.

    Edit:

    You are not wrong. Trust me, your answer is correct. But, you might want to evaluate it a little further and simplify the expression to 6(x^3)(sqrt(x^4+1)). If it still says that you are wrong, there is something wrong with the website.

Still have questions? Get your answers by asking now.