1. given:
csc(x) + sin(x)
2. definition of csc(x) :
1/sin(x) + sin(x)
3. combining fractions with a common denominator:
(1 + sin²(x))/sin(x)
4. expanding 1 = cos²(x) + sin²(x) :
(cos²(x) + sin²(x) + sin²(x))/sin(x)
5. simplifying:
(2 sin²(x) + cos²(x))/sin(x)
6. employing the same identity as in (4) :
(2 (1 - cos²(x)) + cos²(x))/sin(x)
7. expanding 2 (1 - cos²(x)) :
(2 - 2 cos²(x) + cos²(x))/sin(x)
8. simplifying:
(2 - cos²(x))/sin(x)
