Trigonometry: X=cosθ,Y=sinθ

This collection of interactive excel sheets looks at a circle of radius 1 and the corresponding values generated for cosθ and sinθ.

The first interactive sheet illustrates that for the unit circle, X = cosθ and Y = sinθ. The value of θ can be adjusted.

The second sheet generates angles from 0° to 360° and shows how these relate to the equivalent acute angle in the first quadrant. The following sheet similarly shows how the angles 0° to -360° relate to the equivalent angle in quadrant 1.

In the fourth interactive sheet students are to find solutions in the range 0° to 360° for given values of sinθ and cosθ. In the following sheet the solutions are to be in the range -180° to 180°. Click on each question number to see the solutions illustrated on a graph.

The next sheet displays two triangles demonstrating the trigonometric ratios of the angles 30°, 45° and 60°. The final sheet illustrates all trigonometric ratios for multiples of 30° and 45°.

Note
This program was designed by be viewed on a screen with a resolution of 1024 x 768. Users may have to adjust the resolution of their screen for the pages to display as was originally intended. The program uses macros which need to be enabled on users’ machine.