$$\int sin^2xcos^4xdx$$
$$=$$
$$\int \frac{1}{2}(1-cos2x)\left(\frac{1}{2}(1+cos2x)\right)^2dx$$
$$=$$
$$\frac{1}{8}\int (1-cos2x)(1+cos2x)^2dx$$
$$=$$
$$\frac{1}{8}\int (1-cos^22x)(1+cos2x)dx$$
$$=$$
$$\frac{1}{8}\int sin^22x(1+cos2x)dx$$
$$=$$
$$\frac{1}{8}\int sin^22xdx+\frac{1}{8}\int sin^2xcos2xdx$$
Bundan sonrası kolay artık.