c:16777216 x^9-79036416 x^8 y+149707008 x^7 y^2-147529728 x^6 y^3-319832064 x^6 y+81119232 x^5 y^4+1389617856 x^5 y^2-23887872 x^4 y^5-2447247168 x^4 y^3+665127936 x^4 y+2985984 x^3 y^6+2255257728 x^3 y^4-1831796208 x^3 y^2-1174051584 x^2 y^5+1653791904 x^2 y^3-918330048 x^2 y+332563968 x y^6-407516832 x y^4+1689982380 x y^2-40310784 y^7-35586864 y^5-985488444 y^3+387420489 y=0 の 特異点達を 求めて下さい; https://math.stackexchange.com/questions/662768/degree-of-the-dual-curve-to-xy2-z3  を味読し; c の 双対曲線 c^★ を求め 其の 2重接線達 を求めて下さい;