JEE Main 20188 April
- Exam
- JEE Main
- Year
- 2018
- Date
- 8 April
- Subject
- Mathematics
- Chapter
- Parabola
JEE Main 2018 · 8 April · Mathematics · Parabola
Tangent and normal are drawn at P(16, 16) on the parabola y ^ 2 =...
Tangent and normal are drawn at $ on the parabola , which intersect the axis of the parabola at , respectively. If is the center of the circle through the points and then a value of $tan \theta is:
Options
- A
- B
- C
- D
Correct answer
C.
Step-by-step solution
Equation of tangent at is
Equation of normal at \left({x}_{1}, {y}_{1}\right)y - {y}_{1} = - \dfrac{{y}_{1}}{2a} ( x - {x}_{1} )P ( 16, 16 )∴2y = x + 16y + 2x = 48A\left(- 16, 0\right)B ( 24, 0 )APBABAB= \left(4, 0\right)PC = \dfrac{4}{3}PB$
$tan \theta = \left|\dfrac{\dfrac{4}{3} + 2}{1 - 2 \times \dfrac{4}{3}}\right| = \left|\dfrac{10}{- 5}\right| = 2