Question

Find the equation of the circle with:

Centre (−2, 3) and radius 4.

Answer 1

Let (h, k) be the centre of a circle with radius a.
Thus, its equation will be \[\left( x - h \right)^2 + \left( y - k \right)^2 = a^2\]

Here, h = −2, k = 3 and a = 4

∴ Required equation of the circle:

\[\left( x + 2 \right)^2 + \left( y - 3 \right)^2 = 4^2\]

\[\Rightarrow \left( x + 2 \right)^2 + \left( y - 3 \right)^2 = 16\]