The question goes like this:

If the approximate formula sin(x)=x-(x^3)/3! is used and |x|＜1 (radian), then the error is numerically less than ____

I got confused because even terms are omitted in Maclaurin series for sin(x) (such as a2(x^2) and a4(x^4)

If Lagrange error bound's applied, the term after -(x^3)/3! would actually be a4*x^4= 0

If the series were treated as an alternating series, there's no specific number given for x since the question only says |x|＜0

How should I approach this question?

Thanks in advance!