# Maths C2 Curve help!

• May 11th 2008, 01:44 AM
languages
Maths C2 Curve help!
Please can someone help me with this:

The Curve with equation y = f (x) passes through the point (8,7)
Given that

f ' (x) = 4x^1/3 - 5

find f(x)

Many thanks,

languages
• May 11th 2008, 01:51 AM
Moo
Hello,

Quote:

Originally Posted by languages
Please can someone help me with this:

The Curve with equation y = f (x) passes through the point (8,7)
Given that

f ' (x) = 4x^1/3 - 5

find f(x)

Many thanks,

languages

Find the primitive of f'(x) :

An antiderivative of $x^n$ is $\frac{x^{n+1}}{n+1}$. Here, n=1/3

An antiderivative of a is ax. Here, a=-5.

The primitive will be the sum of these antiderivatives, to which you add a constant c.

The fact that the curve passes through the point (8,7) will help you find c.