# Geometric Sequence

• Oct 23rd 2008, 12:17 PM
magentarita
Geometric Sequence
Find x so that x - 1, x, and x + 2 are consecutive terms of a geometric sequence.

• Oct 23rd 2008, 12:23 PM
masters
Quote:

Originally Posted by magentarita
Find x so that x - 1, x, and x + 2 are consecutive terms of a geometric sequence.

In a geometric sequence, there must be a 'common ratio' between consecutive terms. So...

$\frac{x}{x-1}=\frac{x+2}{x}$

Solve for x.
• Oct 23rd 2008, 05:42 PM
magentarita
again....
Quote:

Originally Posted by masters
In a geometric sequence, there must be a 'common ratio' between consecutive terms. So...

$\frac{x}{x-1}=\frac{x+2}{x}$

Solve for x.

I had no idea that there must be a common ratio in terms of geometric sequence.