Write the equation of a circle centered at a point M of radius R if M (2; -1) R = 3.

We need to write the equation of a circle centered at point M and radius R if the coordinates of point M (2; -1) are known and the radius value R = 3.

Let’s first recall the formula for writing the equation of a circle:

(x – a) ^ 2 + (y – b) ^ 2 = R ^ 2.

where (a; b) are the coordinates of the center of the circle, and R is the radius of the circle.

We just have to substitute the values in the formula and we get the equation of the circle:

(x – 2) ^ 2 + (y – (-1)) ^ 2 = 3 ^ 2;

(x – 2) ^ 2 + (y + 1) = 9.

now we can write the equation of the circle in response.

Answer: (x – 2) ^ 2 + (y + 1) ^ 2 = 9.