Ответ:

{sin=-((((sqrt(3)*i-1)*(x*cos^3+1)^((1/3)))/(2*x^((1/3))))), sin=(((sqrt(3)*i+1)*(x*cos^3+1)^((1/3)))/(2*x^((1/3)))), sin=-(((x*cos^3+1)^((1/3))/x^((1/3))))}