TRIGONOMETRIC RATIOS
Some standard angles :
\(f(-\theta)\) for all the values of ‘\(\theta\)’:
\(\begin{gathered} \sin \left( { - \theta } \right) = - \sin \theta ; \hfill \\ \cos ec\left( { - \theta } \right) = - \cos ec\theta \hfill \\ \cos \left( { - \theta } \right) = \cos \theta \hfill \\ \end{gathered} \)
\(\begin{gathered} \sec \left( { - \theta } \right) = \sec \theta \hfill \\ \tan \left( { - \theta } \right) = - \tan \theta ; \hfill \\ \cot \left( { - \theta } \right) = - \cot \theta \hfill \\ \end{gathered} \)
sign will change for sin, cosec, tan and cot values. There is no change in cos and sec values.