Part of the course(s): Trigonometry

Composite Trig Function Problems
a.k.a. "nested" inverse trig functinos

These are those problems where you've got sines and cosines inside of each other. Like you'll take "the inverse cosine of the sine of pi/3" or "the tangent of the inverse cotangent of 1". Very complicated looking, but if you work from inside out you can do these all day long.