how i fix this problem?

x=0.2;
exact=exp(x);
syms approx approxL approxI
Et=inline('(exact-approx)/exact)*100%','approx');
>> Et(3)
??? Undefined variable INLINE_INPUTS_.

Error in ==> inlineeval at 11
eval(INLINE_INPUTEXPR_);

Error in ==> inline.subsref at 27
    INLINE_OUT_ = inlineeval(INLINE_INPUTS_, INLINE_OBJ_.inputExpr, INLINE_OBJ_.expr);

Answer 1

[Star Strider]

Use symfun (in R2012a and later), instead of inline:

x=0.2;
exact=exp(x);
syms approx approxL approxI
Et=symfun(((exact-approx)/exact)*100 ,approx);