请教高手，我这段程序有什么错误？？？急急急

[jiasudu.m]
function (x) = jiasudu[u]
%
% u(1)=alpha-2
% u(2)=omaga-2
% u(3)=omaga-3
% u(4)=theta-2
% u(5)=theta-3
%
r2=50;
r3=150;
%
a=[r3*sin(u(5)) 1;-r3*cos(u(5)) 0];
b=[-(r2*u(1)*sin(u(4))+r2*u(1)^2*cos(u(4))+r3*u(3)^2*cos(u(5)));r2*u(1)*cos(u(4))-r2*u(1)^2*sin(u(4))-r3*u(3)^2*sin(u(5))];
%
x=inv(a)*b;