Let a line y= m x( m >0) intersect the parabola, y^2=x at a point P, other than the origin. Let the tangent to it at P meet the x -axis at the point…

Let a line $\displaystyle y=\mathrm{m} x(\mathrm{~m}>0)$ intersect the parabola, $\displaystyle y^2=x$ at a point P , other than the origin. Let the tangent to it at P meet the $\displaystyle x$-axis at the point Q. If area $\displaystyle (\Delta \mathrm{OPQ})=4$ sq. units, then m is equal to \_\_\_\_.