∴f′(x)=(ex)′(sinx-cosx)+ex(sinx-cosx)′=2exsinx,
∵x∈(2kπ,2kπ+π)時(shí),f′(x)>0,x∈(2kπ+π,2kπ+2π)時(shí),f′(x)<0,
∴x∈(2kπ,2kπ+π)時(shí)原函數(shù)遞增,x∈(2kπ+π,2kπ+2π)時(shí),函數(shù)f(x)=ex(sinx-cosx)遞減,
故當(dāng)x=2kπ+π時(shí),f(x)取極大值,
其極大值為f(2kπ+π)=e2kπ+π[sin(2kπ+π)-cos(2kπ+π)]
=e2kπ+π×(0-(-1))
=e2kπ+π,
又0≤x≤2014π,
∴函數(shù)f(x)的各極大值之和
S=eπ+e3π+e5π+…+e2013π
=
eπ(1?(e2π)1007) |
1?e2π |
=
eπ(1?e2014π) |
1?e2π |
故選:B.