InterviewSolution
Saved Bookmarks
| 1. |
If `3x^(2)+2lambda xy + 3y^(2)+(6-lambda)x+(2lambda-6)y-21=0` is the equation of a circle, then its radius isA. 1B. 3C. `2sqrt(2)`D. none of these |
|
Answer» Correct Answer - B We have, `3x^(2)+2lambda xy + 3 y6(2)+(6-lambda)+(2lambda-6)y-21=0 " " ...(i)` This equation will represent a circle, if Coeff. of `xy=0rarr lambda = 0` Putting `lambda=0` in (i), we obtain `x^(2)+y^(2)+2x-2y-7=0` Clearly, it represents a circle of radius `= sqrt(1+1+7)=3`. |
|