Explanation

This is a product of two functions, so we apply the product rule:

d​[u⋅v]/dx=u′⋅v+u⋅v′

Here,

• u=x^2, sou′=2x

• $v = sin(x)$, so $v' = cos(x)$

Now apply the rule:

$$f'(x) = 2x cdot sin(x) + x^2 cdot cos(x)$$