Question

If the angle $\theta =-60°$, find the value of $\sin \theta ,\cos \theta ,sec\theta ,\tan \theta$.

Answer 1

$$\begin{gathered} \mathrm{Given}\mathrm{that}:\theta =-60° \\ \mathrm{Now},\mathrm{we}\mathrm{have}\mathrm{the}\mathrm{following}: \\ \sin \theta =\sin (-60°) \\ =-\sin 60°[\because \sin (-\theta )=-\sin \theta ] \\ =-\frac{\sqrt{3}}{2} \\ \cos \theta =\cos (-60°) \\ =\cos 60°[\because \cos (-\theta )=\cos \theta ] \\ =\frac{1}{2} \\ \sec \theta =sec(-60°) \\ =sec60°[\because sec(-\theta )=sec\theta ] \\ =2 \\ \tan \theta =\tan (-60°) \\ =-\tan 60°[\because \tan (-\theta )=-\tan \theta ] \\ =-\sqrt{3} \end{gathered}$$