Trigonometry Formulas: There are very few topics in mathematics that trouble students more than trigonometry and calculus. In fact, it is the base of many advanced math concepts and is also utilized ...

Sec(a-b) = cos(a+b) / cos^2a - sin^2b I'm trying to prove this, by turning the left side into the right. I am stuck. Presumably you have already done the sum and difference formulas for sin and cos.

Use sum and difference formulas for the trig functions to find angles ...