Question

Find the angles, θ<0<360, that satisfy the equation below, to the nearest 10th of a degree.

cos(θ)= -√7/5

Answer 1

`\cos( \theta) = \frac{ - \sqrt{} 7}{5} \\ \theta = \cos {}^( - 1) ( \frac{ \sqrt{} - 7}{5} ) \\ \theta = 58.1 \degree, \: 121.9 \degree, \: 238.1 \degree`