The derivative of f of x is just going to be equal to 2x by the power rule. And the derivative of g of x is just the derivative of sine of x. And we covered this when we just talked about common derivatives. Derivative of sine of x is cosine of x. And so now we're ready to apply the product rule. This is going to be equal to f prime of x times g of x. So f prime of x, the derivative of f, is 2x times g of x, which is sine of x, plus just our function f, which is x squared, times the derivative of g, times cosine of x.