JEE Main20249 Apr 2024Evening ShiftMathematicsParabolaActual
Let A, B and C be three points on the parabola y^2=6 x and let the line segment A B meet the line L through C parallel to the x -axis at the point D . Let M and N respectively be the feet of the perpendiculars from A and B on L . Then ( A M B N C D )^2 is equal to _________
Correct answer
0
Step-by-step solution
aligned & m _ AB = m _ AD & 2 t ₁+ t ₂ = 2 a ( t ₁- t ₃ ) at ₁^2- & at ₁^2- = a t ₁^2- t ₁ t ₃+ t ₁ t ₂- t ₂ t ₃ & = a ( t ₁ t ₃+ t ₂ t ₃- t ₁ t ₂ ) & AM = |2 a ( t ₁- t ₃ ) |, BN = |2 a ( t ₂- t ₃ ) |, & CD = | at ₃^2- | aligned aligned & CD = | at ₃^2- a ( t ₁ t ₃+ t ₂ t ₃- t ₁ t ₂ ) | &= a | t ₃^2- t ₁ t ₃- t ₂ t ₃+ t ₁ t ₂ | &= a | t ₃ ( t ₃- t ₁ )- t ₂ ( t ₃- t ₁ ) | & CD = a | ( t ₃- t ₂ ) ( t ₃- t ₁ ) | & ( AM BN CD )^2= 2 a ( t ₁- t ₃ ) 2 a ( t ₂- t ₃ ) a ( t ₃- t ₂ ) ( t ₃- t ₁ ) ^2 & 16 a ^2=16 9 4 =36 al