Write the standard form of the equation for the given information.

Question

center (4,9) and tangent to the x-axis

Answer 1

Tangent to the x axis means that the circle touches the X axis

Known information: center (4,9)

The radius of the circle must be 9 units long because the edge of the circle will intersect with the X axis.

standard form of a circle: (x-h)^2 + (y-k)^2 = r^2

where (h,k) are coordinates of center

h=4

k=9

r=9

(x-4)^2 + (y-9)^2 = 81