hi everyone, thanks for taking your time in reading this, but I've been stuck on this question for a bit and just wondering what i'm doing terribly wrong.
Write down the coordinates of the centre, and the length of the radius of the following circle:
a) 2x^2+2y^2-8x+5y+3=0
My working out was:
1) 2(x^2-4x+y^2+2.5)= -3
2) x^2-4x+y^2+2.5= -1.5
3) (x^2-4x+4)+(y^2+2.5+1.5626)= -1.5-4-1.5625
4) (x-2)^2+(y-1.25)^2= -7.0625
Therefore, centre is (2,-1.25), but then i realised that r^2 was negative and you could not really square root it to find the radius of the circle. The answers say the answer for the radius is 1/4√65. Any ideas?
Write down the coordinates of the centre, and the length of the radius of the following circle:
a) 2x^2+2y^2-8x+5y+3=0
My working out was:
1) 2(x^2-4x+y^2+2.5)= -3
2) x^2-4x+y^2+2.5= -1.5
3) (x^2-4x+4)+(y^2+2.5+1.5626)= -1.5-4-1.5625
4) (x-2)^2+(y-1.25)^2= -7.0625
Therefore, centre is (2,-1.25), but then i realised that r^2 was negative and you could not really square root it to find the radius of the circle. The answers say the answer for the radius is 1/4√65. Any ideas?