A a-b=1． B a-b=-1． C a-b=8． D a-b=-8．

A e^-xf(e^-x)+f(x)． B -e^-xf(e^-x)+f(x)． C e^-xf(e^-x)-f(x)． D -e^-xf(e^-x)-f(x)．

A <img width="291" height="40" src="https://www.beizhujiaoyu.com/uploads/202208/20211222222938_6803.jpg" /> B <img width="291" height="39" src="https://www.beizhujiaoyu.com/uploads/202208/20211222222940_1323.jpg" /> C <img width="312" height="39" src="https://www.beizhujiaoyu.com/uploads/202208/20211222222940_8218.jpg" /> D <img width="311" height="39" src="https://www.beizhujiaoyu.com/uploads/202208/20211222222942_2574.jpg" />

A -1 B 0 C 1 D 2

A ln²x+C． B -ln²x+C． C lnx-ln²x+C． D 2lnx-ln²x+C．

A x² B 1-cosx C <img width="106" height="21" src="https://www.beizhujiaoyu.com/uploads/202208/20211222222945_0709.jpg" /> D x-sinx

A F₁(x)+F₂(x). B F₁(x)-F₂(x). C F₁(x)·F₂(x). D <img width="54" height="50" src="https://www.beizhujiaoyu.com/uploads/202208/20211222222946_5074.jpg" />

A 0．2 B 0．3 C 0．4 D 0．5

A 没有等于零的r-1阶子式，至少有一个不为零的r阶子式 B 有不等于零的r阶子式，所有r+1阶子式全为零 C 有等于零的r阶子式，没有不等于零的r+1阶子式 D 所有r阶子式不等于零，所有r+1阶子式全为零

A <img width="24" height="41" src="https://www.beizhujiaoyu.com/uploads/202208/20211222222948_6949.jpg" /> B <img width="41" height="40" src="https://www.beizhujiaoyu.com/uploads/202208/20211222222949_2886.jpg" /> C <img width="24" height="41" src="https://www.beizhujiaoyu.com/uploads/202208/20211222222950_8354.jpg" /> D <img width="40" height="41" src="https://www.beizhujiaoyu.com/uploads/202208/20211222222951_3980.jpg" />