Question

Write the standard equation of a circle with center (0, 3) and radius 7.

Answer 1

`\text{The standard form of the circle:}\\\\(x-h)^2+(y-k)^2=r^2\\\\\text{h and k are the x and y coordinates of the center}\\\\\text{We have:}\\\\\text{the center}\ (0;\ 3)\to h=0;\ k=3\\\\\text{the radius}\ r=7\\\\\text{substitute:}\\\\(x-0)^2+(y-3)^2=7^2\\\\x^2+(y-3)^2=49`

Answer 2

Circle equation:

`(x - xo)^(2) + (y - yo)^(2) = {r}^(2)`

Center (0, 3)
Xo = 0
Yo = 3

Radius: 7
r = 7

So:


`(x - 0)^(2) + (y - 3)^(2) = {7}^(2)`

`{x}^(2) + (y - 3)^(2) = 49`

Answer: x^2 + (y - 3)^2 = 49