Question

If a, b, c are in gp then prove that a^3,b^3,c^3 are also in gp

Answer 1

Since a,b,c are in GP  they have a common ratio , 
i.e c/b = b/a  .............. (i)

if a$a^3 , b^3 , c^3$ are in a GP 
 then 
 c3/b3 = b3/ a3  ........ (ii)
 
on cubing equation (1) we get that 
a3, b3, c3 also have a comman ratio.. 
so they are also in an ap

Answer 2

here is the answer....best of luck for ICSE STUDENTS...