Write the equation of the circle, given the following conditions Center (7,-4) Radius 6 units
a. (x-7)^2 + (y+4)^2 = 36
b. (x+7)^2 + (y+4)^2 = 36
c. (x-7)^2 + (y+4)^2 = 6
d. (x-7)^2 + (y-4)^2 = 36

How do I do this?

Question

Write the equation of the circle, given the following conditions Center (7,-4)  Radius 6 units
a. (x-7)^2 + (y+4)^2 = 36
b. (x+7)^2 + (y+4)^2 = 36
c. (x-7)^2 + (y+4)^2 = 6
d. (x-7)^2 + (y-4)^2 = 36

How do I do this?

anonymous · Answer

(x-7)^2 + (y+4)^2 = 36

directrix · Answer

You need to know the standard form for the equation of a circle so that you can identify the center and radius.

(x -( h)) ^2 + (y -( k))^2 = r^2

h = 7, k = -4, and r = 6

(x - 7) ^2 + (y - (-4) )^2 = 6^2

(x - 7) ^2 + (y + 4) )^2 = 36  --> Option A