I need help understanding the solution to this problem

Step 1 of 3 A Consider the recurrence T(n) = T(n-1)+n In order to solve a recurrence, first a solution should be guessed and then need to find the required constant values using mathematical induction. Then need to prove that the guessed solution works perfectly. Guess the solution as T (n) =0(n) Use the substitution method to prove that the guess is correct. So, it is required to prove that T(n)sch? .....(1) Where is a constant such that c>0