题目

matlab 解三角函数方程弧度与角度问题
[theta11,theta12,theta13]=solve('(94*cosd(theta13))/5-10*sind(theta11)*sind(theta13)-(79*cosd(theta11)*sind(theta12)*sind(theta13))/2 - (59*cosd(theta12)*sind(theta11)*sind(theta13))/2=29.4281',' (59*sind(theta11)*sind(theta12))/2 - (79*cosd(theta11)*cosd(theta12))/2=10.1192','-(94*sind(theta13))/5 - 10*cosd(theta13)*sind(theta11) - (79*cosd(theta11)*cosd(theta13)*sind(theta12))/2 - (59*cosd(theta12)*cosd(theta13)*sind(theta11))/2=30.8552');
这个三元一次方程,用cosd等表示就不对呢?

提问时间：2021-04-06

答案

[theta11,theta12,theta13]=solve('(94*cos(theta13))/5-10*sin(theta11)*sin(theta13)-(79*cos(theta11)*sin(theta12)*sin(theta13))/2 - (59*cos(theta12)*sin(theta11)*sin(theta13))/2=29.4281',' (59*sin(theta11)*sin(theta12))/2 - (79*cos(theta11)*cos(theta12))/2=10.1192','-(94*sin(theta13))/5 - 10*cos(theta13)*sin(theta11) - (79*cos(theta11)*cos(theta13)*sin(theta12))/2 - (59*cos(theta12)*cos(theta13)*sin(theta11))/2=30.8552','theta11,theta12,theta13')
要先把sind角度制的换成sin弧度制函数.否则解方程不认这个基本函数.接出来之后再弧度制再换成角度制就OK了.