Question

Find cos θ for θ = 45°

Answer 1

90°- θ = θ - 45°

= 20 = 135°

= θ - 65.5°

Answer 2

`\cos( \theta) \\ \cos(45) = \cos( (\pi)/(4) ) \\ = (1)/( √(2) ) \\ or \\ = ( √(2) )/(2)`