求证明行列式方程a b b 1 p p^3b a b=(a+2b)(a-b)² 1 q q^3=(p-q)(q-r)(r
2个回答

第一题:a b b b a b b a b

b a b=- a b b= b b a[两次行交换]

b b a b b a a b b

b a b b a b

= 0 (b-a) (a-b) = { 0 (b-a) (a-b) }÷b

0 (b-a)(b+a) b(b-a) 0 0 -(a-b)(a+2b)

=(a+2b)(a-b)² [对角线法则]

第二题:1 p p^3 1 p p^3

1 q q^3 = 0 (q-p) (q-p)(q^2+p^2+qp)

1 r r^3 0 (r-p) (r-p)(r^2+p^2+rp)

1 p p^3 1 p p^3

=0 (q-p) (q-p)(q^2+p^2+qp) = { 0 (q-p) (q-p)(q^2+p^2+qp) }÷(q-p)

0 0 (q-p)(r-p)(r^2-q^2+rp-qp) 0 0 (q-p)(r-p)(r-q)(r+q+p)

=(p-q)(q-r)(r-p)(p+q+r) [对角线法则]

由于是自己做的,仅供参考!

如果哪里不对也请指正!