- In trigonometry some values of sin, cos and tan are “nice”
- For example sin 30° = ½, tan 45° = 1
- We can find those associated with the angles 30°, 45° and 60° using SOHCAHTOA on isosceles and equilateral triangles
- sin, cos and tan values for 30°, 45° and 60° should be recalled easily
- Memorise either the actual values or how to work them out from the triangle
- sin, cos and tan for 0°, 90°, 180° should also be very familiar
- They can be recalled using the relevant trigonometric graph (see Graphs of Trigonometric Functions)
Exact values and radians
- All of the above applies to radians as well as degrees
- Here is a table of all exact values including radians (see Radian Measure)
How do I find exact values of other angles?
- Exact sin, cos and tan values of multiples of 30°, 45°, 60° can also be found
- This is a combination of recalling the basic values and using the graph
- Draw the triangles for sin, cos and tan of 30°, 45° and 60° on the exam paper so that you can then use them as many times as you need throughout the paper.