Step-by-step explanation:
Remark
Since this is a multiple choice question, you need not worry excessively about solving the equation that sin(4x) and Cos(3x + 13) produce. It can be done, but you will spend a lot time and drink a lot of coffee doing it.
C
The wording of this problem is not the best. 13 is not in any way considered.
- 4x = 4*13 = 52
- 3x+ 13 = 52.
Not only are the two angles equal (52) but they add to 104 which is greater than 90.
11 is the next one you should look at
4*11 = 44
3*11 + 13 = 46
That gives you the right answer, but the question you have to ask yourself is are you answering the question? I don't think you are. The question is the number of degrees in the smaller angle. I think that means that you have already substituted a value for x.
I think the answer is C.