# Thread: Maths Temperature Question.......DEADLYY.Teacher can't do it!!!!!!!!!

1. ## Maths Temperature Question.......DEADLYY.Teacher can't do it!!!!!!!!!

When coffee is made its temperature is 90°C. After t minutes the temperature of the coffee is given by:
90(0.88)t°C

Find after how many minutes the tempertaure of the coffee is 45°C.

Thank you.PLease note that in the above equation for temperature, the t is to the power of 0.88.

2. Originally Posted by eftheking
Thank you.PLease note that in the above equation for temperature, the t is to the power of 0.88.
Now you say it (Or I only see it now )

$\displaystyle 90(0,88)^t = 45$

$\displaystyle 0,88^t = \frac{45}{90} = \frac{1}{2}$

$\displaystyle t = log_{0,88} {0,5}$

$\displaystyle t = 5,4223$

3. much appreciated

4. why use log tho

5. Originally Posted by eftheking
why use log tho
I guess you could have drawn a graph of the function... But that's a long tedious way. What's your idea of solving it?

6. i dint have an idea lol.so its 5minutes then?also, i ahve another question if u would like 2 view.
South Africa is pretty sweet tbh lol

7. Originally Posted by eftheking
i dint have an idea lol.so its 5minutes then?also, i ahve another question if u would like 2 view.
No you will not get such an exact answer with a graph so its not that good an idea, unless you might be using computer graphing software.