Prove by mathematical induction that 1+2+3++n= n(n+1)/2 can someone me with this asap.

Let

In order to prove this by induction, we first need to prove the base case, i.e. prove that P(1) is true:

So, the base case is ok. Now, we need to assume and prove .

states that

Since we're assuming , we can substitute the sum of the first n terms with their expression:

Which terminates the proof, since we showed that

as required