- #1

cscott

- 782

- 1

How do I get from the primary to the secondary solution of a trigonometric equation? This book tells me that the second angle is within [itex]-\pi \leq \theta \leq \pi[/itex], in a different quadrent, but I don't follow :\

Thanks.

Please correct me if I'm wrong, but I seem to be getting correct answers

Thanks.

**Edit:**I got it (I think!): I can pick the correct quadrent using the sign of the ratio and knowing where each trig function is positive or negative. Then, I know (as an example) [itex]\sin \theta = +\sin \alpha[/itex], where [itex]\alpha = 180 - \theta[/itex] if we're talking about first and second quadrents.Please correct me if I'm wrong, but I seem to be getting correct answers

Last edited: