But once again, we can use the quotient rule here. So this is going to be the derivative of the top function, which is negative, we're doing that magenta color, that is negative sine of x times the bottom function. So times sine of x, sine of x, minus, minus the top function, cosine of x, cosine of x, times the derivative of the bottom function, which is just going to be another cosine of x, and then all of that over the bottom function squared. So sine of x squared. Now what does this simplify to? Up here, let's see, this is sine squared of x, although we have a negative there, minus cosine squared of x, but we could factor out the negative, and this would be negative sine squared of x plus cosine squared of x. Well, this is just one by the Pythagorean identity, and so this is negative one over sine squared x.