Evaluating Derivative Statements

Which of the following statements is/are true?

I. $\frac{d}{dx}(x^2 \sin(x)) = 2x \sin(x) + x^2 \cos(x)$

II. $\frac{d}{dx}(\cos(3x^2)) = -3\sin(3x^2)$

III. $\frac{d}{dx}(\tan(x)) = \sec^2(x)$