Use a mathematical reference to look up the formula for the secant function, which is the inverse of the cosine of an angle (see link in Resources). Click in cell D2 to enter the secant function ...

In a tutorial [Bramus] takes us through using the trigonometric functions in CSS. These are supported in all major browsers since Chrome 111, Firefox 108 and Safari 15.4.

As you do so, the values of Y translates to sine (red line) and the values of X translate to cosine (blue line): Imgur Now, let's start linking this relationship between the functions and circles ...