Answers

2014-01-15T23:10:05+08:00
In the 4th quadrant, x is positive and y is negative

since it's radius is 2 and it's tangent to the x&y axis the coordinates of the center of the circle is (2,-2)

the equation of the circle is: 
(x-2)^2 + (y+2)^2 = 2^2

0
yes 4y.its plus 101.
4x2+4y2-4x+40y+101=0
sorry i don't know how to solve it..i've tried the usual completing the square but i'll still end up getting a negative radius. You can't square a number and get a negative answer-it's always positive. So, that might not be a circle...
it means the circle is no graph or imaginary...that's my answer.am i correct?
yes