A prоgrаmmer writes the fоllоwing function to updаte а database of credits earned by students. function credits = total_credits(creds_earned) persistent num_credits if isempty(num_credits) num_credits = creds_earned; else num_credits = num_credits + creds_earned; end credits = num_credits; end What is output after the following commands are made from the command window?total_credits(12); total_credits(9); total_credits(15);