Question

Given that cos a = -12/3 and a is an angle in Quadrant II and that sin Beta = 3/5 is an angle in Quadrant I. Determine

a) cos (a + Beta)

b) sin (Beta - a)

Answer 1

Dear visitor
The statement of your question is confusing: cosine's value can't be less than -1. Cosine is bounded function with
values between -1 and 1. In Real Analysis.