What is the centre and radius of the circle x^2+y^2-6x+4y=-4
First make left =0x2+y2-6x+4y+4=0Second put same terms together(x2-6x)+(y2+4y)+4=0Complete the Square (do a square (X+b)2 that gives you you x2 and x terms, repeat with y) these give you the centre values(x-3)2=x2-6x+9(y+2)2=y2+4y+4Put in your completed squares minus the constant value as you only want the x2 and x term(x-3)2-9+ (y+2)2-4+4=0Rearrange to get the radius (put constants on right)(x-3)2+ (y+2)2=9Therefore centre (3,-2) radius = sqrt(9)=3
