# Homework Help: Simplification on Tangens

1. Aug 24, 2006

### philipp2020

hi

i have a question on a simplification

tan (45° + b) - tan (45° -b)

Then I put on both sides the Theorems for Addition. But I am not sure if my result is right. What is most possible simplification here?

is it 1 + 4 tan b / 1 - tan^2 b ???

Thanks very much for an answer.

Greetings

Philipp

Last edited: Aug 24, 2006
2. Aug 24, 2006

### BobG

Double check the tangent sum and difference identities. Your denominator is good, but I can't figure out what mistake you could have made to get the numerator that you did.

If you get the numerator correct, there's another identity that allows you to simplify the fraction.

3. Aug 25, 2006

### philipp2020

ah so the numerator is only 4 tan b and not plus 1 yes...

oh ok... i see

then at the end it will be just 2 * tan 2b