计算下列方阵的行列式：第一行 1 a b c 第二行a 0 0 0 第三行b 0 0 0 第四行c 0 0 0,

1,a,b,c
a,0,0,0
b,0,0,0
c,0,0,0
r2-a*r1:
1,a,b,c
0,-a^2,-ab,-ac
b,0,0,0
c,0,0,0
r3-b*r1:
1,a,b,c
0,-a^2,-ab,-ac
0,-ab,-b^2,-bc
c,0,0,0
r4-c*r1:
1,a,b,c
0,-a^2,-ab,-ac
0,-ab,-b^2,-bc
0,-ac,-bc,-c^2
r3-(b/a)r2:
1,a,b,c
0,-a^2,-ab,-ac
0,0,0,0
0,-ac,-bc,-c^2
r4-(c/a)r2:
1,a,b,c
0,-a^2,-ab,-ac
0,0,0,0
0,0,0,0
=1*(-a^2)*0*0
=0