An Induction Problem, What Am I Supposed To Prove? I have encountered an induction problem which I don't understand. What I don't understand is what it is asking me to prove. I don't want a solution. The problem is: 
If $u_1=5$ and $u_{n+1}=2u_n-3(-1)^n$, then $u_n=3(2^n)+(-1)^n$ for all positive integers. 
Am I supposed to prove  $u_{n+1}=2u_n-3(-1)^n$ or $u_n=3(2^n)+(-1)^n$ is true for all positive integers? 

You are supposed to prove $u_n=3(2^n)+(-1)^n$.
$u_1=5$ and $u_{n+1}=2u_n-3(-1)^n$ are the conditions you are supposed to make use of.
