1. The problem statement, all variables and given/known data Prove that 3^n >= 2n+1 for all natural numbers. 2. Relevant equations 3^n >= 2n+1 [is bigger or equal to] 3. The attempt at a solution 3*1>=2+1 True for n=1 Assumption: 3^k>=2k+1 3^(k+1)>=2k+3 3^k*3>=2k+3 (2k+1)*3>=2k+3 <---can I just substitute 2k+1 into 3^k as per my assumption, because 3^k is bigger, and (2k+1)*3 is bigger than 2k+3? If so, is the proof complete? Thanks in advance.