xy=k n y^2=x. solving them we get that they intersect at x=k raised to 2/3 n y = k raised to 1/3.
since the curves intersect at right angles this implies that the tangent drawn to them at these points to the curves are perpendicular to each other.supposing the equations to b y=mx+cand applying the condition of tangency differently for both the curves we get the equations of tangents respectively as x+k^1/3 y=2k^2/3 n x-2 k^1/3 y+k^2/3=0
applying the condition of tangency m1 x m2 =o, we get the desired result ie 8k^2=1 did u get it?