If A B 90. 190120 bce was the first to construct a table of values for a trigonometric functionHe considered every triangleplanar or sphericalas being inscribed in a circle so that each side becomes a chord that is a straight line that connects two points on a curve or surface as shown by the inscribed triangle ABC in. But theres a whole realm of trig that isnt taught at school such as s i n n t h e t a which you can simplify using the equation e i x c o s x i s i n x.
Also if we chose AC as the base and BC as the perpendicular.
Important Trigonometry Formula for Sum and Difference Of Two Angles. Similarly for a unit circle for which radius is equal to 1 and th is the angle. If A B 90. Cosecant of angle th cosecth Hypotenuse Perpendicular.