Question

Which of the following line is a diameter of the circle $x ^ { 2 } + y ^ { 2 } - 6 x - 8 y - 9 = 0$.

• A. $3 x - 4 y = 0$
• B. $4 x - 3 y = 9$
• C. $x + y = 7$
• D. $x - y = 1$

Answer 1

Answer: (C)

$x + y = 7$

Answer 2

Centre (3, 4) is satisfying only $x + y = 7$.