In general terms, it is not possible to establish symbolic explicit analytic expressions of the operating point and transient analysis for circuits containing diodes modelled using an exponential function. Therefore, this work propose replacing the diode for an equivalent circuit obtained by using a power series and a Taylor series consecutively. Finally, we present a symbolic solution for some circuits that include diodes; resulting for the best case: for DC analysis a relative error of 1E-11 and for transient analysis a relative error ≤ 5E-4.