Q.

If the line 3x – 2y + 12 = 0 intersects the parabola 4y=3x2 at the points A and B, then at the vertex of the parabola, the line segment AB subtends an angle equal to          [2025]

1 tan1(119)  
2 tan1(97)  
3 tan1(45)  
4 π2tan1(32)  

Ans.

(2)

Given, 3x – 2y + 12 = 0

 y=3x+122

Put value of 'y' in 4y=3x2, we get

 2(3x+12)=3x2

 x22x8=0  x=2,4

   y = 3, 12

Let A(–2, 3) and B(4, 12)

Since, vertex of parabola is O(0, 0).

  mOA=32, mOB=124=3

  tan θ=|mOAmOB1+mOA×mOB|=|3231+(32)×3|

 tan θ=97  θ=tan1(97).