>>297
　C = { (x,y) | x=3cosθ, y=2sinθ, 0≦θ<2π}
　dx = -3sinθdθ,
　dy = 2cosθdθ,
　x^4 + 4x^3･y + y^4 = 81(cosθ)^4 + 216(cosθ)^3･sinθ + 16(sinθ)^4,
　x^4 + 4xy^3 + x^2 = 81(cosθ)^4 + 96cosθ(sinθ)^3 + 9(cosθ)^2,

>>305
2(x-2)(x-1)(x+1)(x+2)