Thursday 25 February 2016

elementary number theory - Prove by induction that $2^{2n} – 1$ is divisible by $3$ whenever n is a positive integer.

I am confused as to how to solve this question.



For the Base case $n=1$, $(2^{2(1)} - 1)\,/\, 3 = 1$, base case holds




My induction hypothesis is:
Assume $2^{2k} -1$ is divisible by $3$ when $k$ is a positive integer



So, $2^{2k} -1 = 3m$



$2^{2k} = 3m+1$



after this, I'm not quite sure where to go. Can anyone provide any hints?

No comments:

Post a Comment

real analysis - How to find $lim_{hrightarrow 0}frac{sin(ha)}{h}$

How to find $\lim_{h\rightarrow 0}\frac{\sin(ha)}{h}$ without lhopital rule? I know when I use lhopital I easy get $$ \lim_{h\rightarrow 0}...