One over cosine of x is secant, so this is just secant of x squared. So that was pretty straightforward. Now let's just do the inverse of the, or you could say the reciprocal, I should say, of the tangent function, which is the cotangent. So that was fun, so let's do that. D dx of cotangent, not cosine, of cotangent of x, well, same idea. That's the derivative with respect to x. And this time, let me make some sufficiently large brackets.