If A1 contains the result of your LOG10 formula (e.g., =3DLOG10(1.234)),
then the antilog is =3D10^A1.
Although that does return exactly 1.234 in that case, in general do
not expect the antilog to exactly equal the parameter of LOG10. For
example, if A1 is =3DLOG10(PI()), =3D10^A1-PI()=3D0 is FALSE(!) [1].
Also, do not expect the antilog to exactly match mathematical
equalities. For example, if A1 is =3DLOG10(4.5)+LOG10(2) [2], =3D10^A1=3D9
is FALSE(!).
Infinitesimal differences are due to the limitations of computer
arithmetic as well as to the fact that generally LOG10 and the power
operator (^) use generating functions or algorithms to approximate
their results (when the exponent is non-integer in the case of the
power operator).
-----
Endnotes
[1] But =3D10^A1=3DPI() is TRUE. The difference is due to Excel
heuristics which try to hide inequalities when the difference is
[2] We expect LOG10(4.5)+LOG10(2) =3D LOG10(4.5*2) =3D LOG10(9) based on
mathematical equalities.