求级数 sin(pi/6)+sin(2pi/6)+sin(3pi/6)+.+sin(npi/6)+.的部分和.（pi为圆周率）

一个周期之内：sin(π/6) = 1/2sin(2π/6) = (根号3)/2sin(3π/6) = 1sin(4π/6) = (根号3)/2sin(5π/6) = 1/2sin(6π/6) = 0sin(7π/6) = -1/2sin(8π/6) = -(根号3)/2sin(9π/6) = -1sin(10π/6) = -(根号3)/2sin(...