# Cooling of a cup of tea

- Author:
- majo

- Topic:
- Function Graph

Let's have a delicious cup of tea

## The initial temperature of the tea is 75°C and the room temperature is 24°C. Sketch the curve that you think it models the cooling temperature of the tea

## Is it linear? is it quadratic? Justify

## These are the temperatures at the beginning and after 3, 6 and 9 minutes have passed

## Sketch the points in these set of axes

## Can you see any tendency here? Explain briefly

## This is the curve which models the cooling the temperature of the cup of tea

## What is the y-intercept?

## Does it have any roots? Why/Why not?

## This is the equation of the curve

y = 24 + 51e

^{-0.106x}## What is the 'e' number?

## Now that you know that the formula is that one, with 'e' approx to 2.72 and using the formula

Find the temperatures after 15, 20 and 40 minutes
Remember: y = 24 + 51e^{-0.106x}

## What would you think it happens if the room temperature is another one?

Explain