I keep getting trig function powers wrong due to formatting.

I am on U substitution, however, I haven't been able to ask questions on here until recently. The most recent iteration of this issue happened when I was trying to annotate

(sin^4(x))/4  the only way I found I could enter it was ((sin(x))^4)/4 and that is apparently not the same expression, at least when measured against the answer key. 

I can't seem to format the power to the trig function, and the only work around I have found is to enter (sin(x)sin(x)sin(x)sin(x)) this, however, is rather cumbersome when the power is greater than just 2. 

I do apologize if I have posted in error on this portion of the forum, I have clicked the help button at the bottom right and asked this question in a few ways, but I find I can't poise the question in a way that the engine will find actually related information.