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