Find the point on the z-axis which is equidistant from the points A(1, 5, 7) and B(5, 1, -4).
Consider, C(0,0,z) point which lies on z axis and is equidistant from points A(1, 5, 7) and B(5, 1, -4).
∴ AC = BC
Squaring both sides,
= 
1 +25+ z2 -14z +49 = 25 + 1 + z2 +8z +16
-22z = -33
Z = 1.5
The point C is (0,0,1.5).
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