Trigonometry Examples

$\cos (\frac{3 π}{13}) + \cos (\frac{5 π}{13}) = 2 \cos (\frac{9 π}{13}) \cos (\cos (π))$

Step 1

The left side $1.10311563$ does not equal to the right side $- 0.61385338$ , which means that the given statement is false.

False