06Bexactvals

= Exact Values =

In VCE Maths Methods (and Specialist Maths), unless told otherwise, you should always leave your answer as an exact value. This means you leave your answer without evaluating surds, p, e, fractions etc.

The most common use for exact values is with trig ratios. For the standard angles, you only need to remember two values:
 * sin 30º = ½
 * tan 45º = 1

media type="custom" key="8158976" From these two values, we can media type="custom" key="8159004" and media type="custom" key="8159026" using Pythagoras:

media type="custom" key="8159040" width="80" height="80"

Then from these two triangles, we can obtain the desired exact value:



You should also know the exact values for 0º and 90º.

Return to Specialist (Summary of Trigonometry)

Return to Methods (Trigonometry)