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.

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." ...

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 ...

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 ...

This approach works because sine and cosine are the building blocks of all other trigonometric functions. For example, to simplify tan θ · csc θ, convert both functions: (sin θ/cos θ) · (1 ...

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).