这个问题无法重复

>> [a,b,c]=solve(a==sin(b),c==2+a,b==cos(c))
a =
-0.21293942373923748200472002911458
b =
-0.21458239935687114053031493652659
c =
1.7870605762607625179952799708854
>> version
ans =
7.14.0.739 (R2012a)

会不会软件问题。 至少我这边没问题

>> [a,b,c]=solve(a==sin(b),c==2+a,b==cos(c))
a =
-0.21293942373923748200472002911458
b =
-0.21458239935687114053031493652659
c =
1.7870605762607625179952799708854
>> version
ans =
7.14.0.739 (R2012a)

自己的问题