[求助]

ares1986

(x*cosα+y*sinα)^2/a^2+(y*cosα-x*sinα)^2/b^2=1
已知(x1,y1),(x2,y2),(x3,y3),求a,b,α
有谁能帮我解出这个方程的?

cjsh

算法： Q := RealField(); P := PolynomialRing(Q, 5: Global); PP := PolynomialRing(Q, 5: Global); PP; EXPAND((x*cosz+y*sinz)^2/a^2+(y*cosz-x*sinz)^2/b^2);展开 SOLVE(x*cosz+y*sinz)^2/a^2+(y*cosz-x*sinz)^2/b^2=1解方程 MAPLE下，解方程有好几个函数，挑个能解不定方程的-------我没试， MAPLE下1000次方都能解 Polynomial ring of rank 5 over Q Order: Lexicographical Variables: x, y, z, a, b