if the approximation is less than the true value, the error is positive. Also, for Eqs. (4.3) to (4.5), the denominator
may be less than zero, which can also lead to a negative error. Often, when performing computations, we may not
be concerned with the sign of the error but are interested in whether the absolute value of the percent relative error
is lower than a prespecified tolerance εs. Therefore, it is often useful to employ the absolute value of Eq. (4.5). For
such cases, the computation is repeated until