Question

The equations of the lines joining the vertex of the parabola $y^2=6x$ to the points on it which have abscissa $24$ are

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

Answer 1

The correct option is B $2y\pm x=0$

The equation of line joining the vertex of parabola $y^2=bx$ .

To the point on it which have abscissa $24$ are

If abscissa is $24$

$y^2=bx=b\left(24\right)\Rightarrow y=\pm 12$

And vertex is $(0,0)$

So equation if line through $(0,0)$ and $(24,\pm 12)$

is $y=mx$

$y=\pm \frac{12}{24}x2y\pm x=0$