Given Degrees [math]\longrightarrow[/math] x[math]^\circ[/math]*[math]\frac{\pi}{180^\circ}[/math]=angle in radians[br]Given Radians [math]\longrightarrow[/math] x rad * [math]\frac{180^\circ}{\pi}[/math]=angle in degrees[br][br]Generally don't simplify angle measurements with [math]\pi[/math] into decimals. [br]i.e. don't simplify [math]\frac{4\pi}{3}[/math] to 4.1887902047863909846168578443727. [br]Keeping [math]\pi[/math] in your answer is much more precise

The unit circle is a circle with a radius of one centered at the origin. There are various points on the circle that help us find the value of certain trig function expressions[br][br]The coordinates of the points on the unit circle are the cosine and sine values of the labeled angles x (degrees or radians). These values will turn into the points (cos(x), sin(x)) which will end up being on the circle.[br][br]For example for x=[math]\frac{3\pi}{4}[/math] or 135[math]^\circ[/math] [br]the coordinates for that angle are (cos(135[math]^\circ[/math]), sin(135[math]^\circ[/math])) or (cos([math]\frac{3\pi}{4}[/math]), sin([math]\frac{3\pi}{4}[/math])) [math]\longrightarrow[/math] [math]\left(\frac{-\sqrt[]{2}}{2},\frac{\sqrt{2}}{2}\right)[/math] in quadrant II

[math]tan\left(x\right)[/math]=[math]\frac{sin\left(x\right)}{cos\left(x\right)}[/math][br]The x coordinates of points on the unit circle are cos(x) values[br]The y coordinates of points on the unit circle are sin(x) values[br]To find the [math]tan\left(x\right)[/math] values you divide the y value by the x value in the coordinate like this [math]\frac{sin\left(x\right)}{cos\left(x\right)}[/math][br]For example, the tangent value of [math]\frac{2\pi}{3}[/math] or 120[math]^\circ[/math] is [math]\frac{\sqrt{3}}{2}[/math]/ [math]\frac{-1}{2}[/math] = [math]-\sqrt{3}[/math][br]See the Applet below for all tangent values in the unit circle