Error using sym>convertChar （sym使用报错）

这种情况，多数情况下设置一个变量就好了，不要用符号输入`

> f = sym('x^2');

Error using sym>convertChar (line 1448)
Character vectors and strings in the first argument can only specify a variable or number. To evaluate
character vectors and strings representing symbolic expressions, use ‘str2sym’.

Error in sym>tomupad (line 1214)
S = convertChar(x);

Error in sym (line 211)
S.s = tomupad(x);

**>> syms x;
>> f = sym(x^2);
>> int(f)**

ans =

x^3/3