Get Answers to all your Questions

header-bg qa

Equation of a common tangent to the circle, x^2 + y^2 - 6x = 0 and the parabola, y^2 = 4x , is:

  • Option 1)

    2\sqrt{3}y = 12x +1

  • Option 2)

    \sqrt3 y = x +3

  • Option 3)

    2\sqrt{3}y = -x -12

  • Option 4)

    \sqrt3y = 3x +1

Answers (1)

best_answer

 

Angle of intersection of two curves -

The angle of intersection of two curves is the angle subtended between the tangents at their point of intersection.Let  m1  &  m2 are two slope of tangents at intersection point of two curves then

tan\theta=\frac{[m_{1}-m_{2}]}{1+m_{1}m_{2}}

- wherein

where \theta is angle between two curves tangents.

 

From the concept

Equation of tangent to parabola y^{2}=4ax

is y=mx+\frac{a}{m}

Here, parabola, y^{2}=4x

So, tangent \Rightarrow y=mx+\frac{1}{m}

This is also a common tangent to circle x^{2}+y^{2}-6x=0

radius =3

\Rightarrow \frac{\left | 3m^{2}+1 \right |}{\sqrt{m^{4}+m^{2}}}=3

\Rightarrow m=\pm \frac{1}{\sqrt{3}}

\Rightarrow tangent are  x+\sqrt{3}y+3=0

and x-\sqrt{3}y+3=0


Option 1)

2\sqrt{3}y = 12x +1

Option 2)

\sqrt3 y = x +3

Option 3)

2\sqrt{3}y = -x -12

Option 4)

\sqrt3y = 3x +1

Posted by

admin

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE