From the seventeenth century, scales of trigonometric functions appeared on drawing instruments such as rules and sectors. The discovery of the logarithm at the beginning of the century led to another ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. This 64-page booklet was received ...

Trigonometry is a branch of mathematics that deals with the relationships between the angles and sides of triangles. One of the most important trigonometric rules is the Cosine Rule, also known as the ...

There are a few rules we have for trig functions and how they behave. $$ \sin(A \pm B) = \sin A \cos B \pm \cos A \sin B \\ \cos(A \pm B) = \cos A \cos B \mp \sin A \sin B \\ \tan(A \pm B) = ...