Move the slider to change the Standard angle[br]and see [br][list][br][*]a triangle with sides labeled for trigonometric functions[br][*]the Reference angle in each corresponding quadrant[br][/list][br]A play button at the bottom will show the angle increasing.[br][br]The right side shows the value of Sine, Cosine and Tangent as the angle is changed. A trace of the values is also shown so you can see how the functions vary. ctrl-F will clear the traces.

This is one of the main principles behind using the trigonometric functions and inverse trigonometric functions for any angle.[br]The absolute value of the x coordinate can replace the Adjacent side and the y coordinate can replace the Opposite side of a right triangle.[br]Adjustments can then be made for the sign of the trigonometric functions based on which quadrant the reference triangle is in.[br][br]Also, shown are the values of trigonometric functions for both reference and standard angles. [br][br]How do the signs of the trigonometric functions vary in the different quadrants?[br][br]How would you find the inverse function of tangent in quadrant III ?