Question

Find the centre and radius of the radius of the circle:
$x^2+y^2+8x+10y-8=0$.

Answer 1

Given Equation can be Converted to Standard Equation of Circle as follows

$(x^2+8x+16)+(y^2+10y+25)=8+25+16\Rightarrow (x+4{)}^2+(y+5{)}^2=7^2..........\left(1\right)$

and Standard equation of Circle is : $(x+f{)}^2+(y+g{)}^2=r^2.........\left(2\right)$

where, $r$ = radius of Circle

$(-f,-g)$ is the center

Comparing (1) and (2)

$center:(-4,-5)$

$radius:7$