Question

Find cos θ for θ = 45°

Answer 1

Answer:

$\cos( \theta) \\ \cos(45) = \cos( \frac{\pi}{4} ) \\ = \frac{1}{ \sqrt{2} } \\ or \\ = \frac{ \sqrt{2} }{2}$

Answer 2

90°- θ = θ - 45°

= 20 = 135°

= θ - 65.5°