This worksheet reviews derivatives of the 6 main trig functions (sine, cosine, tangent, cosecant, secant, cotangent), and also reviews unit circle values. Students should have the derivatives of trig functions memorized, and know the unit circle values of the 6 trig functions by memory. Students do not need to know any other rules (such as product rule). After students complete each problem (or the entire worksheet), they match the answers to the corresponding letters to solve the riddle. The p