If the lines $\frac{x-1}{2}=\frac{y+1}{3}=\frac{z-1}{4}$ and $\frac{x-3}{1}=\frac{y-\mathrm{k}}{2}=\frac{\mathrm{z}}{1}$ intersect, then the value of k is

If $y=\sqrt{x+\sqrt{y+\sqrt{x+\sqrt{y+\ldots \ldots \ldots \ldots \ldots \ldots . \infty}}}}$, then $\frac{\mathrm{d} y}{\mathrm{~d} x}=$

The graph with correct feasible region of L.P.P. for the constraints $2 x+y \leqslant 10, y \leqslant x, y \leqslant 2, x, y \geqslant 0$ is …

The distance of the point $\mathrm{P}(3,4,4)$ from the point of intersection of the line joining the points $\mathrm{Q}(3,-4,-5), \mathrm{R}(2,-3,1)$ and the plane $2 x+y+z=7$ is