Question

X^2 + y^2 – 2x + 8y – 10 = -3
Equation of a circle

Answer 1

`\underline{\,\bold{(x-1)^2+(y+4)^2=24}\,}`

Explanation:

`x^2 + y^2-2x + 8y-10 = -3\\\\x^2 -2x + y^2 + 8y-10 = -3\\\\\underline{x^2 -2\cdot x\cdot1+1^2} +\underline{ y^2 + 2\cdot y\cdot4+4^2}-10 = -3+1^2+4^2\\\\(x-1)^2+(y+4)^2-10=-3+1+16\\\\(x-1)^2+(y+4)^2=24`

The circle center is at (1, -4) and the radius is r = √24 = 2√6