Let a, b, c be distinct non-negative numbers. If the vectors ai + aj + ck, i + k and ci + cj + bk lie on a plane, then c is
(a) the AM of a and b
(b) the GM of a and b
(c) The HM of a and b
(d) equal to zero.
Answer is (b) the GM of a and b
Explanation:
Given
a(0 – c) – a(b – c) + c(c) = 0
c2 = ab
Thus,
c is the GM of a and b.
