F(x)=e^xsinx
F’(x)= e^xsinx+e^xcosx
=e^x(sinx+cosx)
= e^x√2(√2/2*sinx+√2/2*cosx)
=e^x√2(sinπ/4sinx+cosπ/4cosx)
=e^x√2cos(x-π/4)
讨论其正负号即可
F(x)=e^xsinx
F’(x)= e^xsinx+e^xcosx
=e^x(sinx+cosx)
= e^x√2(√2/2*sinx+√2/2*cosx)
=e^x√2(sinπ/4sinx+cosπ/4cosx)
=e^x√2cos(x-π/4)
讨论其正负号即可