f(x)=x^3-7x find f'(a) Help Don't know Anything!!!?

Answer 1

f(x)=x^3-7x
f(a) = a^3 - 7a

f'(a) = 3a² - 7

Take the derivative of a function term by term; you will probably need to read up on this if you aren't familiar with how to do it, since it's a little complex for a short Y!A explanation. Do a web search on derivatives, and find the site that works for you!

http://archives.math.utk.edu/visual.calculus/2/definition.12/index.html

http://en.wikipedia.org/wiki/Derivative

Answer 2

f' (efe prime) means you want the first derivative of the function f(x). f'(a) means you want a value of f'(x) at x=a

So.... let's figure out the derivative first

f(x)=x^3 - 7x
f'(x)=3x^2 - 7 ... you know how to do this, right? Move the power to the front, then reduce the term of power by 1

Then subsitute a for x
f'(a) =3a^2 - y

That's your answer.

Answer 3

f'(x) is 3x^2 -7 - standard differentiation; you should know how to do this.

f'(a) is f'(x) evaluated at x = a; you should know that

f'(a) = 3a^2-7

Answer 4

f'(a)=3a^2-7