And so zero times cosine of x, that is just zero. And so all we are left with is sine of x over cosine of x squared. And there's multiple ways that you could rewrite this if you like. You could say that this is the same thing as sine of x over cosine of x times one over cosine of x. And of course, this is tangent of x times secant of x. Secant of x. So you could say derivative of secant x is sine of x over cosine squared of x, or it is tangent of x times secant of x. So now let's do cosecant.