Prove the following by the principle of mathematical induction:

Let P(n):


Step 1: Let us check if P(1) is true or not,


P(1):


Therefore, P(1) is true.


Step 2: Let us assume that P(k) is true, now we have to prove that P(k + 1) is true.


P(k):


P(k+1):


From P(k) we can see that,


P(k + 1):


P(k + 1):


P(k + 1):


Therefore, P(k + 1) is true.


Hence, Proved by mathematical induction.


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