mathematica 求函数极限, 求解

Question

In[1] := Cos[x^2] /. x -> 0
Out[1] =
（是不是这么书写， 不会用啊）
SetDelayed::write : "Tag In in In[1] is Protected. ‘™˜ButtonBox["",
Appearance->{Automatic, None},
BaseStyle->"Link",
ButtonData:>"paclet:ref/message/General/write",
ButtonNote->"SetDelayed::write"]"

Answer 1

In[1]:=以及Out[1]=都不需要手动输入的，它们是系统自己生成的，直接输入Cos[x^2]/.x->0即可