把原式乘以sinx后再除以sinxrn原式={1/2(sinx)+1/2(sin2x-sin0)+1/2(sin3x-sinx)+1/2(sin4x-sin2x)+………+1/2[sin(n+1)x-sin(n-1)x]}/sinxrn=1/2[sin(nx)+sin(n+1)x]/sinxrn=sin{[(2n+1)/2]x}cos(x/2)/sinx
数字电子技术基础,运用公式法,将下图中的式子化简成最简与或是
把原式乘以sinx后再除以sinxrn原式={1/2(sinx)+1/2(sin2x-sin0)+1/2(sin3x-sinx)+1/2(sin4x-sin2x)+………+1/2[sin(n+1)x-sin(n-1)x]}/sinxrn=1/2[sin(nx)+sin(n+1)x]/sinxrn=sin{[(2n+1)/2]x}cos(x/2)/sinx