Trigonometric formulas for tangent?

1. Apr 29, 2008

quantumgenius

using those formulas, how would you solve
tan 11 pi
-----
8

and cot 195

also, how would you prove tan (x +y ) = tan x
and tan ( pi/4 -x) = 1 - tan x
---------
1 + tan x

thank you so much for any help

2. Apr 29, 2008

quantumgenius

the -------------- and what's under that belongs on the right side of the equation

3. Apr 29, 2008

Integral

Staff Emeritus

Also I am moving this to the homework help forum, in the future please post this type of question there.

4. Apr 29, 2008

tron_2.0

latex is a good tool, im learnign it myself

5. Apr 30, 2008

HallsofIvy

Staff Emeritus
It's really a very bad idea to mix radians and degrees which it looks like you are doing here. Do you know what tan($\pi/4$) is? Do you know the "half angle" formula for tangent?

You wouldn't- it's not true!

What is tan(x+ y)?? And what is tan($\pi/4$)?

thank you so much for any help[/QUOTE]