JEE Main 20246 AprilMorning Shift
- Exam
- JEE Main
- Year
- 2024
- Date
- 6 April
- Shift
- Morning Shift
- Subject
- Mathematics
- Chapter
- Parabola
JEE Main 2024 · 6 April · Morning Shift · Mathematics · Parabola
Let a conic C pass through the point (4,-2) and P(x, y), x ≥ 3 , be...
Let a conic pass through the point and , be any point on . Let the slope of the line touching the conic only at a single point be half the slope of the line joining the points and . If the focal distance of the point on is , then equals ______
Correct answer
0
Step-by-step solution
Slope of line at will be <br />Passes through $(4,-2)\begin{aligned} & \Rightarrow 2 \ln (3)=\ln (1)+C \\ & \Rightarrow C=2 \ln (3) \\ & \Rightarrow 2 \ln (y+5)=\ln (x-3)+2 \ln (3) \\ & \Rightarrow 2\left(\ln \left(\frac{y+5}{3}\right)\right)=\ln (x-3) \\ & \Rightarrow\left(\frac{y+5}{3}\right)^2=(x-3) \end{aligned}\Rightarrow(y+5)^2=9(x-3)$<br />Parabola $\begin{gathered} 4 a=9 \\ a=\frac{9}{4} \end{gathered}$<br /><img src="https://cdn-question-pool.Quantrex.app/pyq/jee_main/9_FUufYi5OdJD2shrSf9IGblPs6QBkRduUJObbXkFz4.original.fullsize.png"><br />\begin{aligned} & d=\sqrt{\left(\frac{7}{4}\right)^2+6^2} \\ & d=\frac{\sqrt{625}}{4} \\ & d=\frac{25}{4} \\ & 12 d=75\end{aligned}$$