Question

A tangent to the parabola y² = 4ax encloses an area of 4a² with the coordinate axes, the equation of the tangent is

• A. 2y – x + 4a = 0
• B. 2y – x – 4a = 0
• C. 2y + x = 4a
• D. None of these

Answer 1

Answer: (B)

2y – x – 4a = 0

Answer 2

Equation of tangent it (at², 2at)

y.2at = 2a(x + at²)

$\frac { 1 } { 2 }$(at²)(at) = 4a²

t³ = 8

Ž t = 2

2y = x + 4a

Ž 2y – x – 4a = 0