If cos theta = frac{{ - 1}}{2} and {0^o}

Question

(c) Given, $\cos 	heta = \frac{{ - 1}}{2}$ and ${0^o} < 	heta < {360^o}$. 

We know that $\cos {60^o} = \frac{1}{2}$ and $\cos ({180^o}

Vedclass · Accepted Answer

${120^o}$ and ${240^o}$

Vedclass · Answer

(c) Given, $\cos 	heta = \frac{{ - 1}}{2}$ and ${0^o} < 	heta < {360^o}$. 

We know that $\cos {60^o} = \frac{1}{2}$ and $\cos ({180^o} - {60^o})$ $ = - \cos {60^o} = - \frac{1}{2}$ or $\cos {120^o} = - \frac{1}{2}$. 

Similarly $\cos ({180^o} + {60^o})$ $ = - \cos {60^o} = - \frac{1}{2}$

or $\cos {240^o} = - \frac{1}{2}.$

Therefore $	heta = {120^o}$ and ${240^o}$.

If $\cos \theta = \frac{{ - 1}}{2}$ and ${0^o} < \theta < {360^o}$, then the values of $\theta $ are

Similar Questions

The set of all values of $\lambda$ for which the equation $\cos ^2 2 x-2 \sin ^4 x-2 \cos ^2 x=\lambda$

If $2\sin \theta + \tan \theta = 0$, then the general values of $\theta $ are

If $\cot \theta + \cot \left( {\frac{\pi }{4} + \theta } \right) = 2$, then the general value of $\theta $ is

Common roots of the equations $2{\sin ^2}x + {\sin ^2}2x = 2$ and $\sin 2x + \cos 2x = \tan x,$ are