# How do you use the Fundamental Theorem of Calculus to find the derivative of #int xsin(πx) # from 1 to x^2?

##### 1 Answer

#### Explanation:

Strictly speaking you don't, because you can't have the variable you're integrating show up in the limits of integration. Assuming you meant something like

We see that the fundamental theorem of calculus states that

Where

Now, we just differentiate both sides

Using the chain rule:

However we know that

But since