Question

Radius of the circle $x^2+y^2+2xcos\theta +2ysin\theta -8=0,$ is

• A. 1
• B. 3
• C. $2\sqrt{3}$
• D. $\sqrt{10}$

Answer 1

The correct option is B 3

$R=\sqrt{co{s}^2\theta +si{n}^2\theta +8}=3$