Q. The point of the parabola $y^{2}\ = 18x$, for which the ordinate is three times the abscissa is
A) (6,2)
B) $( - 2 - 6)$
C) (3,18)
D) (2,6)
Explanation
(d)
Given, $y^{2} = 18x$ …(i)
According to the given condition
$y = 3x$
From Eqs, (i) and (ii),
$(3x)^{2} = 18x\$[form Eq.(i)]
$\Rightarrow \ \ x^{2} = 2x\ \Rightarrow \ \ x = 0,\ 2$
$\Rightarrow \ y = 0,\ \pm 6$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.