The sum of consecutive powers of 9 is a triangular number

Here's a visual proof that [math]\sum_{k=0}^n 9^k[/math] is a triangular number for each value of [math]n \in \mathbb{N}[/math].

 

timteachesmath

 
Resource Type
Activity
Tags
exploration  proof  sequences-and-series  summation  visual 
Target Group (Age)
15 – 18
Language
English (United States)
 
 
 
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