Find the exact solution of the equation 2pi = 6 cos^-1 (3x)
My answer: x= 1/6
Seems too simple to be correct
You are ignoring the important question. You are NOT having trouble working the problem. You are having trouble with your confidence. For this reason, I ask, "Why do you doubt?" Answer the question. My honest question is no less honest than yours. Did you do something wrong on purpose? Can you prove every step of your process? Can you reproduce every step of your process? Answer these questions and gain confidence in your work.
You are assuming that because you are asking for help that you know the kind of help you need. This is a common fallacy.
Show how you worked the problem. Show ALL intermediate steps. Let's figure out why you don't have confidence in your result by the time you get to the end.