The points (4,-2,3), (5,1,2) and (7,7,0) lie on a straight line. State true or false.
True
Let A=(4,-2,3), B=(5,1,2) and C=(7,7,0).
AB=√(5−4)2+(1−(−2))2+(2−3)2=√12+32+12=√11
BC=√(7−5)2+(7−1)2+(0−2)2=√22+62+22=√44=2√11
AC=√(7−4)2+(7−(−2))2+(0−3)2=√32+92+32=√99=3√11
AC=AB+BC. Hence, A, B and C are collinear. The statement is true.