6.证明:-|||-a^2 ab b^2 1-|||-(1) 2a a+b 2b =(a-b)^3.-|||-1 1 1-|||-ax+by ay+bz az+bx 1 x y z-|||-(2) ay+bz az+bx x+by =(a^3+b^3) y z x-|||-az+bx ax+by ay+bz z x y-|||-a^2 ((a+1))^2 ((a+2))^2 ((a+3))^2-|||-b^2 ((b+1))^2 ((b+2))^2 ((b+3))^2 =0.-|||-(3)-|||-c^2 ((c+1))^2 ((c+2))^2 ((c+3))^2-|||-d^2 ((d+1))^2 ((d+2))^2 ((d+3))^2-|||-1 1 1 1-|||-(4) a^4 b^2 c^2 d^2 =(a-b)(a-c)(a -d)(b-c)(b-d)(c-d)(a+b+c+d).-|||-a b C d-|||-a^4 b^4 c^4 d^4-|||-x -1 0 0-|||-(5) 0 x -1 0 =(a)_(3)(x)^3+(a)_(2)(x)^2+(a)_(1)x+(a)_(0).-|||-0 0 x -1-|||-ao a1 a2 a3