And like always, pause this video and see if you could figure it out. Well as you can see here, we have a composite function. So we're taking the secant not just of x, but you could view this as of another expression that I guess you could define, or as of another function. So for example, if we call this right over here u of x. So let's do that. So if we say u of x is equal to three pi over two minus x, we could also figure out u prime of x is going to be equal to derivative of three pi over two, that's just going to be zero, derivative of minus x, so that's just going to be minus one, and you could just view that as a power rule. It's one times negative one times x to the zero power, which is just one.