Question

A circle is centered at the point (-7, -1) and passes through the point (8, 7).

Answer 1

Answer:

Find Radius using distance formula.

$radius = \sqrt{(8 -- 7)^2 +(7--1)^2}$

            =$\sqrt{15^2 + 8^2} = \sqrt{225 + 64 } =\sqrt{289} = 17 units$

Since the point (-15, y) lies on the circle. The distance between (-7, -1) and

(-15, y ) will be 17 units.

So again using distance formula we will find y.

$radius = \sqrt{(-7 --15)^2 + (-1-y)^2} \\\\17 = \sqrt{8^2 + (y+1)^2}\\\\squaring \ both \ sides \\\\289 = 64 + (y+1)^2\\\\289-64=(y+1)^2\\\\225 = (y+1)^2\\\\taking \ squaring \ root\\\\15 = y+1\\\\y=14$

point (-15, 14)