(2 sin(4 x) + 1) cos(x) = 0
sin^5(x) - sin^3(x) + cos(x) + 5 sin(x) cos^4(x) - 10 sin^3(x) cos^2(x) + 3 sin(x) cos^2(x) = 0
x≈2 (3.14159 n + 0.458149), n element Z
