The area of triangle formed by the tangent and the normal to the parabola y^2=4ax both drawn at the same end of the Latus rectum and the axis of the parabola is

Dear student

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 gave given c=1, m=-1, a=k/4 This implies 1=k/4(-1) => k=-4

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