[求助]跪求赐教

[zhouxingli]

程序：function result=Scan_farfild(t0,v0,a,b,c,r,f)
syms t v
A=cos(v0).*sin(t).*cos(v)-sin(v0).*sin(t).*sin(v);
B=cos(t0).*sin(v0).*sin(t).*cos(v)-sin(t0).*cos(t)+cos(t0).*cos(v0).*sin(t).*sin(v);
sin(t1)=(A.^2+B.^2).^(1/2);
t1=asin(sin(t1));
cos(v1)=A/((A^2+B^2)^0.5);
v1=acos(cos(v1));
输入的命令为：t0=0;v0=0;a=1;b=1;c=1;r=3.6e7;f=3e9;Scan_farfild(t0,v0,a,b,c,r,f)
出现问题：??? Error: File: D:\matlab\work\Scan_farfild.m Line: 5 Column: 1
"sin" was previously used as a function,
conflicting with its use here as the name of a variable.
大家帮我看看是什么问题，谢谢了！