Both the sine and cosine functions have outputs between -1 and 1 (because the x and y values can be negative). You can think of these trig functions as a sort of "lookup table." ...

My first idea was to plot the cosine as computed by the series expansion and the table interpolation as a function of the cosine from the TI-31. Here is what that would look like.

We want the slope, but all we have is the angle. What we need is a relationship that relates the two. This relationship is known as the “ tangent function,” written as tan (x). The tangent of ...

This additional symmetry makes functions like cosine incredibly useful. “Much of basic physics begins with understanding the full implications of the trigonometric functions,” said Ken Ono, a ...

Anna F. DeJarnette, Students' Conceptions of Sine and Cosine Functions When Representing Periodic Motion in a Visual Programming Environment, Journal for Research in Mathematics Education, Vol. 49, No ...

The cos⁻¹ function takes the answer to adjacent ÷ hypotenuse (in this example, 16/32), and gives the angle Ɵ. To find Ɵ, calculate cos⁻¹ (16/32).