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(shí),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)