A Circle Is Centered At The Point (-7, -1) And Passes Through The Point (8, 7). The Radius Of The Circle Is ___ Units. The Point (-15, ___) Lies On Th
A circle is centered at the point (-7, -1) and passes through the point (8, 7). The radius of the circle is ___ units. The point (-15, ___) lies on this circle.
Answer: r= 17
The point (-15, 14) lies on the circle
Step-by-step explanation: Since (-7,-1) is the center and (8, 7) is a point on the circle, then we can say that the distance between these two points is the radius. By the distance formula,
r= √((8--7)²+(7--1)²)
= √((15)²+(8)²)
= √289
= 17. This is the radius.
Now given (-7, -1) as the center and (-15, x) being a point on it, we apply once more the distance formula.
r= √((-15--7)²+(x--1)²). But we got that the radius is 17.
So 17= √(64+(x+1)²)
289= 64+(x+1)²
225= (x+1)²
15= x+1
x= 14

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