来自刘斌武的问题
解方程sinx=3sinyx+y=120°
解方程sinx=3sinyx+y=120°
1回答
2020-06-24 23:05
解方程sinx=3sinyx+y=120°
解方程sinx=3sinyx+y=120°
sin(120-y)=3sin(y)sin120cosy-sinycos120=3siny√3/2cosy+1/2siny=3siny√3/2cosy=5/2siny√3/5=tanyy=19.1°x=100.9°h或者sinx=sin(120°-y)=sin120°cosy-cos120°siny=(根号3)(cosy)/2+(siny)/2=3siny得(...