Question

If the equation $p x ^ { 2 } + ( 2 - q ) x y + 3 y ^ { 2 }$ $- 6 q x + 30 y + 6 q = 0$ represents a circle, then the values of p and q are.

• A. 3, 1
• B. 2, 2
• C. 3, 2
• D. 3, 4

Answer 1

Answer: (C)

3, 2

Answer 2

In the equation of circle, there is no term containing xy and coefficient of $x ^ { 2 }$ and $y ^ { 2 }$ are equal. Therefore $2 - q = 0 \Rightarrow q = 2$ and $p = 3$.