Remember that bc/dc are "arbitrary precision" calculators.
You can even use them to verify answers produced by your libc.
Try it!  Example:
  % bc -l
  scale=70
  s(1)
(wait a while 8^)
  .8414709848078965066525023216302989996225630607983710656727517099919104

There is quite careful coding in the bc library to avoid any loss of
precision in all the algorithms provided.