Solving Trigonometric Equations (a third time)

A review of the compound angle formulas, the double angle formulas and the Pythagorean identity.

All the following questions required to find theta (or x or the angle) between 0 radians and 2pi radians.

First a linear example.

A linear example with a double angle. So we needed to solve for 2theta between 0 and 4pi to get theta between 0 and 2pi.

The next example required using the Pythagorean identity and a quadratic trigonometric equation.

Lastly one that required a double angle formula substitution and a surprising result.

Some homework!