Mathematicsindefinite-integrals2020medium
If \int {{{\cos xdx} \over {{{\sin }^3}x{{\left( {1 + {{\sin }^6}x} \right)}^{2/3}}}}} = f\left( x \right){\left( {1 + {{\sin }^6}x} \right)^{1/\lambda }} + c
where c is a constant of integration, then \lambda f\left( {{\pi \over 3}} \right) is equal to