一、选择题
1.函数y=x5·ax(a>0且a≠1)的导数是( )
(A)y′=5x4·axlna
(B)y′=5x4·ax+x5·axlna
(C)y′=5x4·ax+x5·ax
(D)y′=5x4·ax+x5·axlogax
2.(2013·合肥模拟)若抛物线y=x2在点(a,a2)处的切线与两坐标轴围成的三角形的面积为16,则a=( )
(A)4 (B)±4 (C)8 (D)±8
3.(2013·宝鸡模拟)若函数f(x)=excosx,则此函数图像在点(1,f(1))处的切线的倾斜角为( )
