第4小题 化简 在线等
作者&投稿：超香 （若有异议请与网页底部的电邮联系）
化简4小题~
解：√2/4 sin（π/4-x）+√6/4 cos（π/4-x）=√2/2 [1/2 sin（π/4-x）+√3/2 cos（π/4-x）]=√2/2 [cosπ/3 sin（π/4-x）+sinπ/3 cos（π/4-x）]=√2/2 [ sin（π/4-x+π/3）]=√2/2 [ sin（7π/12-x）]=√2/2 [ sin（π/2+π/12-x）]=√2/2 [ cos（π/12-x）]
解：√2/4 sin（π/4-x）+√6/4 cos（π/4-x）=√2/2 [1/2 sin（π/4-x）+√3/2 cos（π/4-x）]=√2/2 [cosπ/3 sin（π/4-x）+sinπ/3 cos（π/4-x）]=√2/2 [ sin（π/4-x+π/3）]=√2/2 [ sin（7π/12-x）]=√2/2 [ sin（π/2+π/12-x）]=√2/2 [ cos（π/12-x）]
