Trigonometry Examples

$\cos (\frac{9 π}{8}) \cos (\frac{3 (9 π)}{8}) - \sin (\frac{9 π}{8}) \sin (\frac{3 (9 π)}{8}) = 0$

Step 1

The left side $0$ is equal to the right side $0$ , which means that the given statement is always true.

True