Thread: integration

the curve f(x) for which f'(x)= 16x+k, where k is a constant, has a stationary point at (2,1), find the value of f(x) when x=7

the answers actually 201 i just can't get the working

Hi

Originally Posted by chaneliman

the curve f(x) for which f'(x)= 16x+k, where k is a constant, has a stationary point at (2,1), find the value of f(x) when x=7

the answers actually 201 i just can't get the working

We know two things :

- That x=2 is a stationary point hence f'(2)=0. This equation can be solved for k.
- That f(2)=1. As f'(x)=16x+k, integrating you get f(x)=... + constant and the equation f(2)=1 will give you the value of the constant.

Then simply compute f(7) and you are done.