If the circle x2 - 4x + 2 + 2y = 4 is translated 3 units to the right and 1 unit down,
what is the center of the circle?
a)
(2.0)
(2,-1)
(5,-2)
d)
(-2, 1/

The answer is below

Step-by-step explanation:

The endpoints of AB are A(2, 3) and B(8, 1). The perpendicular bisector of AB is CD, and point C lies on AB. The length of CD is (root of 10) units.

The coordinates of point C are (-6, 2) (5, 2) (6, -2) (10, 4) . The slope of is -3 -1/3 1/3 3 . The possible coordinates of point D are (4, 5) (5, 5) (6, 5) (8, 3) and (2, 1) (4, -1) (5, -1) (6, -1) .

Solution:

Since CD is the perpendicular bisector of AC, hence line CD is perpendicular to AB and divides line AB into two equal parts.

Point C(x, y) is the midpoint of AB.

hence:

x = (2 + 8) / 2 = 5

y = (3 + 1)/2 = 2

The coordinates of point C = (5, 2)

The slope of line AB is:

slope of AB = (1 - 3) / (8 - 2) = -1/3

Since CD is perpendicular to AB, hence the product of the slope of AB and the slope of CD is -1

slope of AB * slope of CD = -1

slope of CD * -1/3 = -1

slope of CD = 3

Line CD has slope of 3 and pass through C(5, 2). The equation of line CD is:

y - 2 = 3(x - 5)

y = 3x - 13

The possible coordinates of point D are (6, 5) and (4, -1), because this point lie on line CD.