Cosine and sine of an angle θ are defined to be the x and y-coordinates of the point P on the unit circle with the property that the line from O to P makes and angle θ with the positve x-axis. cos(θ) ...

Let's remind ourselves of what the sine graph looks like so that we can see how many solutions we should be expecting: Therefore, from the graph of the function, we can see that we should be expecting ...