
Alan G. answered 03/04/16
Tutor
5
(4)
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To answer a), use the distance formula with (x1, y1) = (-7, 5) and (x2, y2) = (-3, 1):
d = √[(x2 - x1)2 + (y2 - y1)2] = √[(-3 - (-7))2 + (1 - 5)2] = √[42 + (-4)2] = √(16 + 16) = √32 = 4√2 .
You found the correct center by finding the midpoint of the given diameter.
For c), the point symmetric to the y-axis has the x-coordinate change in sign. So, that point would be (5, 3).