If $x = a{\cos ^3}\theta ,y = b{\sin ^3}\theta ,$ then
${\left( {\frac{a}{x}} \right)^{2/3}} + {\left( {\frac{b}{y}} \right)^{2/3}} = 1$
${\left( {\frac{b}{x}} \right)^{2/3}} + {\left( {\frac{a}{y}} \right)^{2/3}} = 1$
${\left( {\frac{x}{a}} \right)^{2/3}} + {\left( {\frac{y}{b}} \right)^{2/3}} = 1$
${\left( {\frac{x}{b}} \right)^{2/3}} + {\left( {\frac{y}{a}} \right)^{2/3}} = 1$
Find the radian measures corresponding to the following degree measures:
$240^{\circ}$
If $\tan \theta = \frac{{x\,\sin \,\phi }}{{1 - x\,\cos \,\phi }}$ and $\tan \,\phi = \frac{{y\sin \,\theta }}{{1 - y\,\cos \,\theta }}$, then $\frac{x}{y} = $
If $\sin \theta = - \frac{1}{{\sqrt 2 }}$ and $\tan \theta = 1,$ then $\theta $ lies in which quadrant
Prove that: $(\cos x+\cos y)^{2}+(\sin x-\sin y)^{2}=4 \cos ^{2} \frac{x+y}{2}$
Find $\sin \frac{x}{2}, \cos \frac{x}{2}$ and $\tan \frac{x}{2},$ if $\tan x=\frac{-4}{3}, x$ in quadrant $II$