2sin²α+2sinαcosα-cos²α 化简
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/02 00:10:28
![2sin²α+2sinαcosα-cos²α 化简](/uploads/image/z/1100404-28-4.jpg?t=2sin%26%23178%3B%CE%B1%2B2sin%CE%B1cos%CE%B1-cos%26%23178%3B%CE%B1+%E5%8C%96%E7%AE%80)
2sin²α+2sinαcosα-cos²α 化简
2sin²α+2sinαcosα-cos²α 化简
2sin²α+2sinαcosα-cos²α 化简
2sin²α+2sinαcosα-cos²α
=-(cos^2α-sin^a)+sin^2a+sin2α
=-cos2α-1/2(-2sin^2a+1-1)+sin2α
=-cos2α-1/2cos2α+1/2+sin2a
=-3/2cos2a+sin2a+1/2