Yup -- in this exercise, it's that easy.
Any instance where you are asked to evaluate a limit, and you have no specific instruction as to method, then you may try substitution first.
However, many limit exercises are cooked up to yield 0/0 by substitution (or some other construction that won't evaluate to a Real number); in those cases, methods other than simple substitution must be used.
Your answer is not correct. Make sure that your machine uses radian mode, when you ask it for sin(11*Pi/4) :cool: