Question -
Answer -
Given:
a, b and c are in GP
b2 =ac {property of geometric mean}
Apply log on bothsides with base m
logm b2 =logm ac
logm b2 =logm a + logm c {using property of log}
2logm b= logm a + logm c
2/logb m= 1/loga m + 1/logc m
∴ 1/loga m, 1/logb m, 1/logc m are in A.P.