Question

Equation of the circle concentric with the circle

x² + y² – 4x – 6y – 91 = 0 and passing through the point

(–4, –5) is –

• A. x² + y² – 4x – 8y – 97 = 0
• B. x² + y² – 2x – 8y – 95 = 0
• C. x² + y² – 4x – 6y – 87 = 0
• D. None of these

Answer 1

Answer: (C)

x² + y² – 4x – 6y – 87 = 0

Answer 2

x² + y² – 4x – 6y – 9 = 0 ...(1)

̃ r = c₁p = $\sqrt { ( 2 + 4 ) ^ { 2 } + ( 3 + 5 ) ^ { 2 } }$= $\sqrt { 36 + 64 }$= 10

So, equation of circle is ̃ (x – 2)² + (y – 3)² = (10)²