Question

If the parabola $y ^ { 2 } = 4 a x$passes through the point $( 1 , - 2 )$, then the tangent at this point is

• A. $x + y - 1 = 0$
• B. $x - y - 1 = 0$
• C. $x + y + 1 = 0$
• D. $x - y + 1 = 0$

Answer 1

Answer: (C)

$x + y + 1 = 0$

Answer 2

$y y _ { 1 } = 2 a \left( x + x _ { 1 } \right) \Rightarrow$ $- 2 y = 2 ( x + 1 )$

∴ Required tangent is $x + y + 1 = 0$