# Small Angle Approximations for Trig Functions

- Author:
- Richard Trimble

- Topic:
- Functions

## Basic approximations

Use the diagram to explain why
and .
Where is a line of length ?
Allowing that use pythagoras to derive .

## Advanced reasoning

Explain why an enlargement of the line by scale factor appears as shown.
Use this to show .
What can you deduce about the value of as ?
Explain why an enlargement of the line by scale factor appears as shown.
Use this to show .
What can you deduce about the value of as ?