[joker_gf]

>> solve('-pi/2-atan(2*x/(25-x^2))=-pi')
Warning: Explicit solution could not be found.
> In solve at 140

ans =

[ empty sym ]

我要解这个方程，系统说是无解
但是我把pi用3.14代替，又有解了。。。

>> solve('-1.57-atan(2*x/(25-x^2))=-3.14')

ans =

-5.0007963903768860882648950427433
4.9992037364504395787507650424125

这是为什么呢？