1. The problem statement, all variables and given/known data First of all this is revision not homework =) question is Xn+1 = Cuberoot ( 17.5-2xn) answer lies between 2 and 3. i know the answer is 2.34 but what i don't get is why it is xn+1 = equation, because when you put xn=2.34 into the equation you get 2.34 out. shouldnt get 3.34 out if its xn+1. whats the purpose of the n+1!!