A curve is represented by the equations, $\mathrm{x} = {\sec }^2\mathrm{t}$ and $\mathrm{y} = \cot \mathrm{t}$ where $\mathrm{t}$ is a parameter. If the tangent at the point $\mathrm{P}$ on the curve where $\mathrm{t} = \mathrm{\pi }/4$ meets the curve again at the point $\mathrm{Q}$ then $\left|\mathrm{PQ}\right|$ is equal to