Q5 of 176 Page 8

If are in A.P. and a + b + c ≠ 0, prove that are in A.P.

Given: a + b + c ≠ 0

and are in AP

To Prove: are in AP

if are in AP

[multiplying each term by a + b + c]

i.e. if are in AP

which is given to be true

Hence, are in AP

Sum of three numbers in A.P. is 21 and their product is 231. Find the numbers.

Sum of three numbers in A.P. is 3 and their product is — 35. Find the numbers.

If a², b², c² are in A.P., show that are in A.P.

If a, b, c are in A.P., prove that

are in A.P.