Vikas TU
Last Activity: 5 Years ago
The line x+y=1 touches the parabola y^2=kx or y^2=4.k/4 x ( Compare with standard eqn y^2=4ax) so a= k/4 and the condition of tangency for the line y=mx+c to a parabola y^2=4ax is that : c=a/m
we ghave given c=1, m=-1, a=k/4 This implies 1=k/4(-1) => k=-4