What is derivative of $\sin ax$ where $a$ is a constant? What is the derivative of $\sin a x$ where $a$ is a constant.

Actually, I'm studying Physics and not so well-versed with calculus. So, I have studied the basic rules of calculus but am stuck here.
I somewhat know about the product rule but don't get what to do if a constant is given in a trigonometric function, be it $\sin ax $ or $\cos ax$. Whatever..
Please help me get my concept clear.

Thank You!

Derivative of $\sin(ax) = a \cos(ax)$ by Chain Rule.
