Question

For the parabola $x^2=8y$ $y=2x+A,y=x+B,y=3x+C,y=-4x+D$ are the tangents of the parabola then the arrangement of $A,B,C,D$ in the descending order is

• A. $A,B,C,D$
• B. $C,B,A,D$
• C. $B,A,C,D$
• D. $C,A,D,B$

Answer 1

The correct option is C $B,A,C,D$

Tangent of parabola is
$y=mx+\frac{a}{m}$

$\Rightarrow A=\frac{2}{2}=1$

$B=\frac{2}{1}=2$

$C=\frac{2}{3}=\frac{2}{3}$

$D=\frac{2}{-4}=\frac{-1}{2}$

$\therefore$ Order is $B,A,C,D.$