Question

a circle passes through the points (2,0) and (8,0) and has the y - axis at a tangent. Find the two possible equations for the circle

Answer 1

The centre of this circle is at 12
1
2
and has radius 12
1
2
, so the equation is (−12)2+2=12
(
x
−
1
2
)
2
+
y
2
=
1
2
.