# Introducing Trig functions

- Author:
- Miss Evans, azb

- Topic:
- Functions

**We have three trigonometric functions: sine, cosine and tangent. These are commonly abbreviated to 'sin' 'cos' and 'tan'. Trigonometric functions work with angles.**

**Move the right angle and change the value of**

**. Look at what happens with the calculations**

How do the trig functions relate to the ratio of sides?

## Cosine

Is cos () =

## Tangent

Is tan () =

## Sine

Is sin () =

## SOHCAHTOA

**SOHCAHTOA is used in Trigonometry to help us remember the functions. What does it mean?
Hint: how does it relate to the above ratios?**

**Make a note of SOHCAHTOA so you can remember how to use it on the next activity.**