Q3 / 92 · NTA Abhyas (JEE Main) 2020 · Mathematics · Parabola

The point of intersection of the tangent to the parabola y2=4x which also touches x2+y2=12 is

  • Correct answer
    A
    -1,0
  • B
    -12,0
  • C
    -2,0
  • D
    -32,0

Solution

Equation of the tangent to the parabola is y=mx+1m
Equation of the tangent to the circle is y=mx±121+m2
For common tangent
1m2=121+m2⇒m4+m2-2=0⇒m2=1⇒m=±1
⇒ Equation of the tangents are y=x+1 and y=-x-1
⇒ Point of intersection of these tangents is -1,0

Hence, the correct answer is option: 'A'.

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