JEE PYQ: Parabola Question 4
Question 4 - 2021 (25 Feb Shift 1)
A tangent is drawn to the parabola $y^2 = 6x$ which is perpendicular to the line $2x + y = 1$. Which of the following points does NOT lie on it?
(1) $(0, 3)$
(2) $(-6, 0)$
(3) $(4, 5)$
(4) $(5, 4)$
Show Answer
Answer: (4)
Solution
Slope of tangent $m_T = \frac{1}{2}$ (perpendicular to $2x + y = 1$). Tangent: $y = \frac{x}{2} + 3 \Rightarrow x - 2y + 6 = 0$. Check: $(5, 4)$: $5 - 8 + 6 = 3 \neq 0$. So $(5, 4)$ does NOT lie on it.
BETA
