A.-2xdx
B.
C.
D.
[单选题]A.-2xdxB.C.D.
[判断题]A.对B.错
[单选题]A.4πB.3/4πC.2πD.4π/3
[单选题]A.B.C.D.
[单选题]A.a=1,b=2B.a=2,b=-1C.a=-1,b=2D.a=-2,b=1
[单选题]A.可导但导函数不连续B.可导且导函数连续C.连续但不可导D.不连续