Do a search on the CORDIC algorithm. It is a table-driven way to compute transcendental functions such SIN, COS, TAN, SQRT, LOG, ... It was developed by Jack E. Volder in the '60 and refined later by ?. Walther.
I know it's been used by TI or HP calculators, and first Intel coprocessors also worked with CORDIC.
(CORDIC: COordinate Rotation DIgital Computer).

Redgards,
Enrique.