设函数f(x)=sin(πx/2+π/4)x

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/05 13:46:15
设函数f(x)=sin(πx/2+π/4)x
x){nϦnHӨд-8Po}AD&H;I0200PJ[jՀuA5kCAthS:1L0LB Ju7 5BW0SHD4$Á-4 blCA6iBl󍻟|VK=(x1ru6<ٽCq']

设函数f(x)=sin(πx/2+π/4)x
设函数f(x)=sin(πx/2+π/4)x

设函数f(x)=sin(πx/2+π/4)x
f(2006)+f(2007)+f(2008)+f(2009)
=sin(2006π/2+π/4)+sin(2007x/2+π/4)+f(2004)+f(2005)
=sin(2006π/2+π/4)+sin(2007π/2+π/4)+sin(2004π/2+π/4)+sin(2005π/2+π/4)
=sin(1004π-π+π/4)+sin(1004π-π/2+π/4)+sin(1002π+π/4)+sin(1002+π/2+π/4)
=sin(-3π/4)+sin(-π/4)+sin(π/4)+sin(3π/4)
=0

f(2008)=f(2004)=sin(π2004/2+π/4)=sin(π2006/2+π/4-π)=-f(2006)
类似的f(2009)=-f(2007) 所以
f(2006)+f(2007)+f(2008)+f(2009)=0