(1-cos2x)+sin2x=根号2(sin2x cosπ/4-cos2x sinπ/4)+1

问题描述:

(1-cos2x)+sin2x=根号2(sin2x cosπ/4-cos2x sinπ/4)+1
这一步骤是怎样得出的呢 请说明

(1-cos2x)+sin2x=根号2Sin(2x-π/4)+1=根号2(sin2x cosπ/4-cos2x sinπ/4)+1我就是不懂这一步怎么推出来的(1-cos2x)+sin2x=根号2Sin(2x-π/4)+1