sin(x) + sin(y) = 1
p x + y = - 3
x + y = p/3
3*y - 3*asin(-1 + sin(y))
-asin(-1 + sin(y))
9.42477796076938 + 3*y + 3*asin(-1 + sin(y))
3.14159265358979 + asin(-1 + sin(y))