Common terms question

Hi! I'm stuck on this question:

'A geometric sequence 𝐺G has first term 8 and common ratio −0.5.
Find an arithmetic sequence that has the same first term and two other terms the same as the corresponding terms of 𝐺G.'

I've got that the geometric sequence is 8, -4, 2, -1, 0.5, . . . but I have no clue how to proceed from here and find an arithmetic sequence that fits those parameters. Any help would be appreciated. :smile:

Reply 1

ghostwalker

17

Original post by Heidi-Heather

Hi! I'm stuck on this question:

'A geometric sequence 𝐺G has first term 8 and common ratio −0.5.
Find an arithmetic sequence that has the same first term and two other terms the same as the corresponding terms of 𝐺G.'

I've got that the geometric sequence is 8, -4, 2, -1, 0.5, . . . but I have no clue how to proceed from here and find an arithmetic sequence that fits those parameters. Any help would be appreciated. :smile:

I don't think they're looking for an analytical solution, rather trial and error. Being systematic, one turns up very quickly.