Question

If the cosine of acute angle α is known, all the other trigonometric ratios for α can be determined.

True

False

Answer 1

True.

Reason: For 0° < α < 90° (acute), sin α = +√(1 − cos^2 α). Once sin α is known you get
- tan α = sin α / cos α,
- cot α = cos α / sin α,
- sec α = 1 / cos α,
- csc α = 1 / sin α.