Question : If $0\leq\theta\leq 90^{\circ}$ and $4\cos^{2}\theta-4\sqrt{3}\cos\theta+3=0$, then the value of $\theta$ is:

Question : The value of $\theta$ $ \left ( 0\leq \theta \leq 90^{\circ} \right )$ satisfying $2\sin^{2}\theta = 3\cos \theta$ is:

Question : If $\sin ^2 \theta-3 \sin \theta+2=0$, then find the value of $\theta\left(0^{\circ} \leq \theta \leq 90^{\circ}\right)$.

Question : If $\left(\frac{\cos A}{1-\sin A}\right)+\left(\frac{\cos A}{1+\sin A}\right)=4$, then what will be the value of $A$? $\left(0^{\circ}<\theta<90^{\circ}\right)$

Question : If $x\sin^{3}\theta +y\cos^{3}\theta=\sin\theta\cos\theta$ and $x\sin\theta-y\cos\theta=0$, then the value of $\left ( x^{2}+y^{2} \right )$ equals: