Thread: Proof by induction.

1. Proof by induction.

Firstly, sorry if this is the wrong section...and also sorry for my crap latex skills!

Prove by induction that
$
M^n = \left(\begin{array}{cc}2^n&3(2^n - 1)\\0&1\end{array}\right)
$

Okey so i did
$
M^n . M
$

Where M is
$
M^n = \left(\begin{array}{cc}2&3\\0&1\end{array}\right)
$

Now i get the
$
2^(n+1)
$

bit required for the induction, but how to i get
$
3.3(2^n - 1) + 3(2^n - 1)
$

into the required form?

Thanks in advanced for any help given
Edit: oo the latex worked! Score! lol.

2. Never mind!
After a few days of wtf...i realized i was multiplying the matrix out wrong...what a froob...
Thanks anyway =)