Question

Determine the equation of the circle with radius 7 and center (4,9).

Answer 1

`\displaystyle{\left(x-4\right)^2 + \left(y-9\right)^2 = 49}`

Step-by-step explanation:

The equation of a circle is:

`\displaystyle{\left(x-h\right)^2 + \left(y-k\right)^2 = r^2}`

Where (h,k) represents the center point and r is the radius. We know the center is at (4,9) and the radius is 7. Thus, substitute in the values:

`\displaystyle{\left(x-4\right)^2 + \left(y-9\right)^2 = 7^2}`

Which eventually becomes:

`\displaystyle{\left(x-4\right)^2 + \left(y-9\right)^2 = 49}`