SOLUTION: Find the exact value of tan(105°)

We use the four facts:

1. 

2. 

3. 

4. 

So we let  and ,

then

 

Now we rationalize the denominator, 
in case your teacher wants you to do that:



[Now you should check that with your calculator.  
For  you get the approximate 
value , and for 
you also get the approximate value ].

Edwin