# Possible Calculation of Logarithms of Cosines in Vlacq's Trigonometria Artificialis

Possible Calculation of Logarithms of Cosines in Vlacq's Trigonometria Artificialis

This Demonstration shows that the logarithms of cosines can be calculated using tables of trigonometric functions calculated to 15 decimals (such as the tables of Pitiscus) and tables of logarithms calculated to 10 decimals (such as Vlacq's 1628 tables) with aid of linear interpolation. Eventual errors are only one unit in the last decimal. In the grid, only the fractional part of is given.

10+|cos(x)|

log

10