（cosθ+isinθ)^6=cos^6θ+6icos^5θsinθ-15cos^4θsin^2θ-20icos^3θsin^3θ+15cos^2θsin^4θ+6icosθsin^5θ-sin^6θ=(cos^6θ-15cos^4θsin^2θ+15cos^2θsin^4θ-sin^6θ)+i(6cos^5θsinθ-20cos^3θsin^3θ...