multiply the derivative of x^2 by the derivative of cos(x)

Let's perform the differentiation:

{(x^{2})}^{'}

2 x

Let's perform the differentiation:

{(\cos (x))}^{'}

- \sin (x)

Let's evaluate:

2 x \cdot - \sin (x)

▷Result: $- 2 x \cdot \sin (x)$