設(shè)參數(shù)方程
,確定了y是x的函數(shù),且f′(t)存在,f(0)=2,f′(0)=2,則當(dāng)t=0時,dy/dx的值等于:()
A.4/3
B.-4/3
C.-2
D.2
設(shè)y=(1+x)
,則y′(1)等于:()
A.2
B.e
C.1/2-ln2
D.1-ln4
已知
,則dy/dx為:()
A.(t2-1)/2t
B.(1-t2)/2t
C.(x2-1)/2x
D.2t/(t2-1)