如何得出数值结果?

jxayong

z1=17;z2=40;m=3;apha=20*pi/180;
r1=0.5*z1*m;r2=0.5*z2*m;
rb1=r1*cos(apha);rb2=r2*cos(apha);
ra1=r1+m;ra2=r2+m;
s1='y=x*tan(apha)';
s2='x^2+(y-r1)^2=ra1^2';s3='x^2+(y+r2)^2=ra2^2';
[x1 y1]=solve(s1,s2);

x1=vpa(x1,5)

x1 =

[ .50000/(1.+tan(apha)^2)*(2.*tan(apha)*r1+2.*(ra1^2-1.*r1^2+tan(apha)^2*ra1^2)^(1/2))]
[ .50000/(1.+tan(apha)^2)*(2.*tan(apha)*r1-2.*(ra1^2-1.*r1^2+tan(apha)^2*ra1^2)^(1/2))]


为什么不能直接出来结果呢?
这里的数值都是已知的,如何才能让它直接得出数值.
如x1=
[-4.02020]
[8.0022   ]
的形式.
谢谢.

feifeifool

s1='y=x*tan(apha)';
s2='x^2+(y-r1)^2=ra1^2';s3='x^2+(y+r2)^2=ra2^2';
[x1 y1]=solve(s1,s2);
你这个纯粹是符号运算.
那就用subs函数求解一些x1,具体的用法doc subs