Question

How do you write the standard form equation of a cirlcle when the diameter is given?

Answer 1

-ends of diameter: (-17,-9) & (-19,-9)

-- The distance between the ends of the diameter is  2,
so the radius is  1.

-- The center of the circle is the midpoint of the diameter ... (-18, -9) .

             (x+18)² + (y+9)² = (1)²


-ends of diameter: (-3,11) & (3,-13)

-- The distance between the ends of the diameter is √612,
so the radius is  (1/2) √612  =  √153 .

-- The center of the circle is the midpoint of the diameter ... (0, -1) .

             (x)² + (y+1)²  =  153