Question

Find the equation of the circle with centre $(-3,4)$ and radius $5$

Answer 1

Since the centre of the circle is $(-3,4)$ and its radius $5$

$\therefore$ the equation of the circle is ${(x-(-3))}^2+{(y-4)}^2=5^2$

$\Rightarrow {(x+3)}^2+{(y-4)}^2=25$

$\Rightarrow x^2+6x+9+y^2-8y+16-25=0$

$\Rightarrow x^2+y^2+6x-8y=0$