Question

If cosx is approximately 0.9511, what is the measurement of x to the nearest degree? Approximately, what is the sin of the angle that is complementary to x?

Answer 1

cosx ≈ 0.9511, so arccos (0.9511) ≈ x, so x≈18°

the complementary angle of x is y=90°-18°=72°
its sinus is sin72°= 0.951