`C_1 and C_2`, are the two concentric circles withradii `r_1 and r_2, (r_1 lt r_2)`. If the tangents drawnfrom any point of `C_2`, to `C_1`, meet again `C_2`, at theends of its diameter, then

Options

A. `x^(2)+y^(2)=2`
B. `x^(2)+y^(2)=4`
C. `x^(2)+y^(2)=64`
D. `x^(2)+y^(2)=36`

Answer

B, C

Explanation

`tantheta=((-5+b)/(a+r)-(-5+b)/(a-r))/(1-((b+5)^(2))/(a^(2)-r^(2)))`
Now, `a^(2)=(r+4)^(2)-5^(2)`
`=r^(2)-9+8r`
`(b-5)^(2)=9`