设y=sin2x，则y′等于().

[单选题]设y=sin2x，则y′等于().A.-cos2xB.cos2xC.-2cos2xD.2cos2x

[单选题]设y=sin2x，则y′等于().A.-cos2xB.cos2xC.-2cos2xD.2cos2x

设(x,y)=sin xy,则(x,y)=sin xy设,则

[单选题]设f′（cos2x）=sin2x，则f（x）等于（）A . cosx+1／2cos2x+cB . cos2x-1／2cos4x+cC . x+（1／2）x2+cD . x-（1／2）x2+c

34 设 y = cos(x^2) sin^2 (1)/(x), 则 y = _.34 (1995, - (1) 题, 3分) 设 $y = \cos(x^2

[单选题]设y=sin(x-2)，则dy=().A.-cosxdxB.cosxdxC.-cos(x-2)dxD.cos(x-2)dx

[单选题]设y=sin(x-2)，则dy=().A.-cosxdxB.cosxdxC.-cos(x-2)dxD.cos(x-2)dx

[单选题]设y=sin(x-2)，则dy=().A.-cosxdxB.cosxdxC.-cos(x-2)dxD.cos(x-2)dx

设y=sin x，则dy=____。填空题（共15题，30.0分）39. (2.0分) 设$y=\sin x$，则$dy=$____。

设 y = y(x) 由参数方程 x = t - sin t，y = 1 - cos t 确定，则 (d^2 y)/(dx^2) = ( )设 $y = y(x