So using just that, we can actually evaluate this, or evaluate g prime of x. So pause the video and see if you can do it. So probably the most intimidating part of this, because we know the derivative of sine of x and cosine of x is this expression here, and we can just rewrite this, or simplify it a little bit, so it takes a form that you might be a little bit more familiar with. So, actually let me just do this on the side here. So pi, pi over the cube root of x squared. Well that's the same thing. This is equal to pi squared over the cube root of x squared.