Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2013-10-20 08:19:10

ninjaman
Member
Registered: 2013-10-15
Posts: 43

geometric series

hello

I have the first term of 30 and the last of 300, I have 7 speeds, 30 is first and 300 is last
I have to find the ratio, to find the middle speed.
im lost, should I be rearranging the formula?:)

Offline

#2 2013-10-20 09:42:45

Nehushtan
Member
From: London
Registered: 2013-03-09
Posts: 615
Website

Re: geometric series

To find the middle term of a G.P. with positive terms, you don’t need to find the common ratio: just multiply the two end terms and take the square root (i.e. take the geometric mean).

Similarly to find the middle term of an A.P., you don’t need the common difference: just add the two end terms and divide by 2 (arithmetic mean).

Last edited by Nehushtan (2013-10-20 23:36:14)


160 books currently added on Goodreads

Offline

Board footer

Powered by FluxBB