来自荣万昌的问题
计算1sin50°+3cos50°=______.
计算1sin50°+
3cos50°=______.
1回答
2020-04-11 17:33
计算1sin50°+3cos50°=______.
计算1sin50°+
3cos50°=______.
1sin50°+3cos50°=cos50°+3sin50°sin50°cos50°=2(12cos50°+ 32sin50°)sin50°cos50°=2(sin30°cos50°+ cos30°sin50°)sin50°cos50°=2sin(30°+50°)sin50°cos50°=2sin80°sin50°cos5...