Question

The equation of tangent to the parabola $y^2=x$ at point $(4,2)$ is

• A. $4y+x+12=0$
• B. $2y-3x+8=0$
• C. $2y+x-8=0$
• D. $4y-x-4=0$

Answer 1

The correct option is D $4y-x-4=0$

Given parabola
$y^2=x$
The equation of tangent at $(4,2)$ is
$T=02\cdot y=\frac{(x+4)}{2}\Rightarrow 4y=(x+4)\Rightarrow 4y-x-4=0$