Question

A particle is moving in clockwise sense on the circumference of a circle x² + y² = 4, it leaves the circle tangentially at a point P and then reflected by a wall parallel to y-axis at A(4, 0). After reflection particle again starts moving along the circle at point Q. R is image of point P in the wall. D₁ and D₂ are the area of DPAQ and DPAR respectively. Then –

• A. D₁ = D₂
• B. D₁ < D₂
• C. D₁ > D₂
• D. None

Answer 1

Answer: (A)

D₁ = D₂

Answer 2

Clearly D₁ = ar (DPAR) = 2ar (DPAM) … (i)

D₂ = ar (DPAR) = 2ar (DPAL) ….(ii)

Now ar (DPAL) = ar (DPAM) … (iii)

From (i), (ii) & (iii) we get

D₁ = D₂