Question

Consider the equation of a circle x^2-2x+y^2-4y-4=0. If the line 2x-y+a=0 is its diameter. Then find the value of a.

Answer 1

Answer:

a=0

Step-by-step explanation:

x²-2x+y²-4y-4=0

(x²-2x+1)+(y²-4y+4)-9=0

(x-1)² + (y-2)² = 3²

Center: (1,2)     radius: 3

(1,2) on line 2x-y+a=0

2*1 - 2 + a = 0

a = 0