Question

The equation of common tangents to the parabola $y^2=8x$ and hyperbola $3x^2-y^2=3$, is

• A. $2x\pm y+1=0$
• B. $2x\pm y-1=0$
• C. $x\pm 2y+1=0$
• D. $x\pm 2y-1=0$

Answer 1

Answer: (A)

$2x\pm y+1=0$

The equation of tangents to $y^2=8x$ is $y=mx+\frac{2}{m}$

Also, the equation of tangent to $\frac{x^2}{1}-\frac{y^2}{3}=1\Rightarrow y=mx\pm \sqrt{m^2-3}$

On comparing, we get $m=\pm 2$

or tangent as $2x\pm y+1=0$