解: (a1,a2,a3,a4) 1 2 1 0-1 4 5 0 0 1 1 1r2+r1 1 2 1 0 0 6 6 0 0 1 1 1r3-(1/6)r2 1 2 1 0 0 6 6 0 0 0 0 1所以 r(a1,a2,a3,a4) = 3, a1,a2,a3,a4 线性相关.