Question

y=e^(-x)*sin2x 求二阶导数

Answer 1

数学之美团为你解答

y ' = - e^(-x) * sin(2x) + e^(-x) * 2cos(2x)

= e^(-x) * [ 2cos(2x) - sin(2x) ]

y'' = - e^(-x) [ 2cos(2x) - sin(2x) ] + e^(-x) [ - 4sin(2x) - 2cos(2x) ]

= - e^(-x) * [ 3sin(2x) + 4cos(2x) ]