Answer:
x = 11
Explanation:
The relationship between the sine and cosine functions can be written as ...
sin(x) = cos(90 -x)
sin(A) = cos(90 -A) = cos(B) . . . . substituting the given values
Equating arguments of the cosine function, we have ...
90 -(3x+4) = 8x -35
86 -3x = 8x -35
86 +35 = 8x +3x . . . . . add 3x+35 to both sides
121 = 11x . . . . . . . . . . . . collect terms
121/11 = x = 11 . . . . . . . . divide by 11
_____
Comment on the solution
There are other applicable relationships between sine and cosine as well. The result is that there are many solutions to this equation. One set is ...
11 +(32 8/11)k . . . for any integer k
Another set is ...
61.8 +72k . . . . . for any integer k