Question

If the length of tangent drawn from the point (5, 3) to the circle $x ^ { 2 } + y ^ { 2 } + 2 x + k y + 17 = 0$be 7, then k =

• A. 4
• B. – 4
• C. – 6
• D. 13/2

Answer 1

Answer: (B)

– 4

Answer 2

According to the condition,

$\sqrt { ( 5 ) ^ { 2 } + ( 3 ) ^ { 2 } + 2 ( 5 ) + k ( 3 ) + 17 } = 7$

$\Rightarrow$ $61 + 3 k = 49 \Rightarrow k = - 4$.