cos²1+cos²2+cos²1°+cos²2°+.+cos²89°
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/04 13:23:16
![cos²1+cos²2+cos²1°+cos²2°+.+cos²89°](/uploads/image/z/5208215-23-5.jpg?t=cos%26%23178%3B1%2Bcos%26%23178%3B2%2Bcos%26%23178%3B1%C2%B0%2Bcos%26%23178%3B2%C2%B0%2B.%2Bcos%26%23178%3B89%C2%B0)
cos²1+cos²2+cos²1°+cos²2°+.+cos²89°
cos²1+cos²2+
cos²1°+cos²2°+.+cos²89°
cos²1+cos²2+cos²1°+cos²2°+.+cos²89°
cos²89°=sin²1°
原式=(cos²89°+cos²1°)+(cos²88°+cos²2°)+.+cos²45°
=44+0.5
=44.5