Posted by kayla on .
Find f'(a) for
f(x)=4x3+1x
f'(a) =?
please please help. i just need to figure out how to do it once and then i can do the rest of my problems

math 
L,
If I'm believe so, you taje the derivative of the function f(x) but instead we're evaluating it at "a".. [f(a)].
So Im assuming your fuction is: 4x^(3)+1x ?
The derivative when can get by using the power rule and bring down the exponent of '3' and mutliply that exponent '3' by the '4' and subtract '1' away from the exponent '3' to arrive at our new exponent. After that, we will take the derivative of 1x which can also be looked at as just (1)(x) which is just "x". So always the derivative of "x" is just the value '1'.
So our answer the the function after taking the derivative would be:
f(a) = 12x^(2)+1 , then we would evaluate that at 'a'. So our final solution would be, 12a^(2)+1..
I hope this helps and also is correct. But check with someone else to confirm I understand your questions correctly..
Good Luck