If $\tan \theta=\frac{1}{\sqrt{5}}$ and $\theta$ lies in the first quadrant, the value of $\cos \theta$ is :
The sum of the series $1+\frac{1}{4}+\frac{1}{16}+\frac{1}{64}+\ldots \ldots . \infty$ is
As $\theta$ increases from $0^{\circ}$ to $90^{\circ}$, the value of $\cos \theta$ :-
Frequency $f$ of a simple pendulum depends on its length $\ell$ and acceleration $g$ due to gravity according to the following equation $f=\frac{1}{2 \pi} \sqrt{\frac{ g }{\ell}}$. Graph between which of the following quantities is a straight line?