The coordinates of a particle moving in $XY$-plane vary with time as $x=4 t ^2 ; y=2 t$. The locus of the particle is a :-
If $\tan \theta=\frac{1}{\sqrt{5}}$ and $\theta$ lies in the first quadrant, the value of $\cos \theta$ is :
The slope of graph as shown in figure at points $1,2$ and $3$ is $m_1, m_2$ and $m_3$ respectively then