f(n)=sin[(n+1/2)π+π/4]+cos[(n-1/2)π+π/4]+tan[(n+1)π+π/4],求f(2011)=?

问题描述:

f(n)=sin[(n+1/2)π+π/4]+cos[(n-1/2)π+π/4]+tan[(n+1)π+π/4],求f(2011)=?

建议:\x09 10.至此,英语练习编制完成.