Question

The equation of the common tangent touching the circle (x - 3)² + y² = 9 and the parabola y² = 4x above the x-axis is

(a) √3y = 3x + 1

(b) √3y = - (x + 3)

(c) √3y = x + 3

(d) √3 y = - (3x + 1)

Answer 1

Correct option: (c) √3y = x + 3

Explanation:

Any tangent to y² = 4x is of the form y = mx + 1/m, (. ^.. a = 1) and the touches the circle

If the tangent touches the parabola and circle above the x-axis, then slope m should be positive.