The variation of the values of sin q and cos q from 0 to 2p
It is clear from the diagram that the values of
2p.
Theorem 5
Statement:
For all values of q, cos (-q) = cos q and sin (-q) = -sin q
Proof:
Fig.(b)
Let XOX' and YOY' be the rectangular coordinate axes. With O as centre and radius unity draw a circle to cut x-axis at A and A' and y-axis at B and B'. Let the rotating line start from OA revolving in anticlockwise line from its starting position revolves in clockwise
Join P and P'. Triangles POM and P'OM are congruent.
2p.
