List of top Mathematics Questions asked in OJEE

Value of $1+cos56^{\circ}+cos58^{\circ}-cos66^{\circ}$ is

Which is true ?

If $2\,sin\,x=\sqrt{\frac{p}{q}}+\sqrt{\frac{q}{p}}$, then

Let $A$ be the square of natural numbers and $x$, $y$ are any two elements of $A$. Then