A.X1/2+X2/3+X3/4
B.X1/4+X2/6+X3/12
C.X1/2+X2/3-X3/6
D.2X1/3+X2/2-X3/6
A.X1和X2同时减小10%,Xm增大
B.X1和X2同时减小到0.81倍,Xm减少
C.X1和X2同时减小到0.81倍,Xm增大
D.X1和X2同时减小10%,Xm减少
函数X1(t),X2(t),…,Xn(t),在区间a≤x≤b上线性相关,则在[a,b]上它们的伏朗斯基行列式W(t)≠0。()
A.错误
B.正确
A.1.678
B.3.074
C.0.698
D.2.376
A.正确
B.错误
A.B点的高程为417.460m
B.B点的高程为417.469m
C.往、返测高差闭合差为0.014m
D.B点的高程为417.467m
E.往、返测高差闭合差为-0.004m
A.220V
B.380V
C.190V