JEE Main 202225 JuneMorning Shift
- Exam
- JEE Main
- Year
- 2022
- Date
- 25 June
- Shift
- Morning Shift
- Subject
- Mathematics
- Chapter
- Parabola
JEE Main 2022 · 25 June · Morning Shift · Mathematics · Parabola
If y = m _ 1 x + c _ 1 and y = m _ 2 x + c _ 2 , m _ 1 ≠ m _ 2 are...
If and are two common tangents of circle and parabola , then the value of is equal to
Options
- A
- B
- C
- D
Correct answer
A.
Step-by-step solution
Equation of the tangent to the parabola can be written as or
Now, the perpendicular distance from \left(0, 0\right)OM = \sqrt{2} ⇒ \left|\dfrac{\dfrac{- 1}{4m}}{\sqrt{1 + {m}^{2}}}\right| = \sqrt{2}⇒ 2\left(16{m}^{2}\right)\left(1 + {m}^{2}\right) = 1 ⇒ 32{m}^{4} + 32{m}^{2} - 1 = 0⇒ {m}^{2} = \dfrac{- {2}^{5} + {2}^{3}\sqrt{16 + 2}}{2 \times {2}^{5}}
= \left|\dfrac{- {2}^{5} + {2}^{3}\sqrt{16 + 2}}{{2}^{3}}\right| = 3\sqrt{2} - 4