On the left, an angle [math]t[/math] is shown in yellow. We know that the cosine and sine of [math]t[/math] are given by the coordinates of [math]A:[/math]  [math]A=\left(\cos t,\sin t\right)[/math][br]On the right, the blue graph consists of points [math]\left(t,\sin t\right)[/math] and the red graph consists of points [math]\left(t,\cos t\right)[/math]. Notice that [math]t[/math] is measured on the horizontal axis. These graphs could also be described by the equations [math]y=\sin x[/math] and [math]y=\cos x,[/math] respectively.