Geometric sequences: How can i proove that (a_(n+1))^2 = a_n *a_(n+2) is a geom. seq?

[Tna1]

How can i proove that:
(a_(n+1))^2=a_n *a_(n+2)
Is a geometric sequence?

 

[tkhunny]

How can i proove that:
(a(n+1))^2=an *a(n+2)
Is a geometric sequence?

Please state, for us, the DEFINITION of a Geometric Sequence.

 

[Steven G]

How can i proove that:
(a(n+1))^2=an *a(n+2)
Is a geometric sequence?

Do you mean (a_n+1)² = a_n*a_(n+2)? If not, then which are subscripts? You can answer this question but you will not get further help until you answer tkhunny's question as you need to know the definition to understand the question. Thanks.