Question

Find the equation of the circle with centre $(-4,-5)$ and radius $6$

Answer 1

Since the centre of the circle is $(-4,-5)$ and its radius $=6$

Then, the equation of the circle is

$\Rightarrow {(x-(-4))}^2+{(y-(-5))}^2=6^2$

$\Rightarrow {(x+4)}^2+{(y+5)}^2=36$

$\Rightarrow x^2+8x+16+y^2+10y+25-36=0$

$\Rightarrow x^2+y^2+8x+10y+5=0$