即求:
sin(1π/3)+sin(2π/3)+sin(3π/3)+sin(4π/3)+sin(5π/3)+sin(6π/3)+sin(7π/3)+……+sin(2012π/3)
該式***2012項:
每6項為壹組,第1組的和=第2組的和=第3組的和=……=第335組的和=0
2012÷6=335……2
原式=sin(2011π/3)+sin(2012π/3)=sin(1π/3)+sin(2π/3)=√3