Exercise - 3.11

Exercise - . . Find the principal value of (i) sin − (ii) cos − (iii) cosec − ( − ) (iv) sec − − (v) tan − √ . . A man standing directly opposite to one side of a road of width x meter views a circular shaped traffic green signal of diameter a meter on the other side of the road. The bottom of the green signal is b meter height from the horizontal level of viewer’s eye. If α denotes the angle subtended by the diameter of the green signal at the viewer’s eye, then prove that α = tan − a + b − tan − b . Trigonometry