How do you describe the translation of circle (x - 1)2 + (y - 4)2 = 25(x1)2+(y4)2=25 that results in an image whose equation is (x + 1)2 + (y - 5)2 = 25(x+1)2+(y5)2=25?

1 Answer
Mar 23, 2016

((-2),(1))

Explanation:

Compare the given equations to the standard equation.

(x - a)^2 + (y - b)^2 = r^2

where (a,b) are the coords of centre and r , is the radius.

so (x-1)^2 + (y-4)^2 = 25 " has centre (1,4)and r =5"

and (x+1)^2 + (y-5)^2 = 25" has centre (-1,5) and r = 5 "

Under a translation the circle retains it's shape, but position is changed.
Just need to consider how the centres have changed.

that is : (1,4) → (-1,5) and as a translation ((-2),(1))