Question

The equation of circle whose diameter is the line joining the points (–5, 3) and (13, –3) is ______.

Options

• x² + y² – 8x – 8y – 74 = 0

• x² + y² – 8y – 74 = 0

• x² + y² – 8x – 74 = 0

• x² + y² + 8x – 74 = 0

Answer 1

The equation of circle whose diameter is the line joining the points (–5, 3) and (13, –3) is x² + y² – 8x – 74 = 0.

Explanation:

By diameter form, the required equation is

(x – x₁) (x – x₂) + (y – y₁) (y – y₂) = 0

⇒ (x + 5) (x – 13) + (y – 3) (y + 3) = 0

⇒ x² + y² – 8x – 74 = 0