This circle has the centre at the origin and a radius of 1 unit. The point P can move around the circumference of the circle. At point P the \(x\)-coordinate is \(\cos{\theta}\) and the \(y ...

The top part of that image is the equation itself. The bottom part is a graph of the equation, which, as you can see, is exactly the same. To be fair, this equation cheats a little bit.

cos(θ) is the x-coordinate of the point P and, sin(θ) is the y-coordinate of the point P. This applet shows how the graphs of sin(θ) and cos(θ) follow directly from the definition of these functions.

This circle has the centre at the origin and a radius of 1 unit. The point P can move around the circumference of the circle. At point P the \(x\)-coordinate is \(\cos{\theta}\) and the \(y ...