化简:cos(15º-α)cos15º-sin(15º-α)sin(-15º)
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/24 01:39:09
![化简:cos(15º-α)cos15º-sin(15º-α)sin(-15º)](/uploads/image/z/2013954-42-4.jpg?t=%E5%8C%96%E7%AE%80%EF%BC%9Acos%2815%26%23186%3B-%CE%B1%29cos15%26%23186%3B-sin%2815%26%23186%3B-%CE%B1%29sin%28-15%26%23186%3B%29)
化简:cos(15º-α)cos15º-sin(15º-α)sin(-15º)
化简:cos(15º-α)cos15º-sin(15º-α)sin(-15º)
化简:cos(15º-α)cos15º-sin(15º-α)sin(-15º)
cos(15º-α)cos15º-sin(15º-α)sin(-15º)
=cos(15º-α)cos15º+sin(15º-α)sin(15º)
=cos(15°-α-15°)
=cos(-α)
=cosα.