# Difference Formula

• March 17th 2010, 06:09 PM
purplec16
Difference Formula
$tan 105$

$tan (60+45)$

$\frac{tan 60 + tan 45}{1 - tan 60 tan 45}$

$\frac{\sqrt{3}+1}{1-\sqrt{3}}$

$-2-\sqrt{3}$

Is this correct?
• March 17th 2010, 06:19 PM
skeeter
Quote:

Originally Posted by purplec16
$tan 105$

$tan (60+45)$

$\frac{tan 60 + tan 45}{1 - tan 60 tan 45}$

$\frac{\sqrt{3}+1}{1-\sqrt{3}}$

$-2-\sqrt{3}$

Is this correct?

check it with your calculator ... you have one, right?

some things you need to check yourself.