When we add or subtract angles, the result is called a compound angle. For example, \(30^\circ + 120^\circ\) is a compound angle. Using a calculator, we find: ...

What do you get for your leap of faith in complex numbers? For one, trigonometry becomes a lot easier. Instead of memorizing several complicated trig formulas, you need only one equation to rule them ...

Solve \(\sqrt 3 \cos x + \sin x = \sqrt 2\), for \(0 \le x \le 2\pi\). First of all we need to put \(\sqrt 3 \cos x + \sin x\) into the form \(k\cos (x - \alpha ...

For one, trigonometry becomes a lot easier. Instead of memorizing several complicated trig formulas, you need only one equation to rule them all: Euler’s 1740 formula. With decent algebra skills ...