AP EAMCET2011MathematicsCircle
If the line y=2 x+c is a tangent to the circle x^2+y^2=5 , then a value of c is
Options
- A2
- B3
- C4
- D5
Correct answer
D. 5
Step-by-step solution
Here, m=2 and c₁=c Given equation of circle is x^2+y^2=5 Here radius a= 5 Since, the line (i) is tangent to the circle. aligned & c=a m^2+1 = 5 (2)^2+1 & c= 5 5 =5 & aligned