You are here:

Calculus/trig. funtion proof.

Advertisement

Expert: Alon Mandes - 5/20/2009


Question
prove the trig. function:

tanx + sinx / 2tanx = cos^2(x/2)

Answer
We know that cos(½α)=√½[1+cosα]. Thus cos²(½α)=½[1+cosα] .
(tanα+sinα)/2tanα=[(sinα/cosα)+sinα]/[2sinα/cosα]=
[(sinα+sinαcosα)/cosα ] * [cosα/2sinα] =
(sinα+sinαcosα)/2sinα =½[1+cosα]. Q.E.D

Alon.  

Calculus

All Answers

Answers by Expert:

Ask Experts

Volunteer

Alon Mandes

Expertise

Kind of questions I can answer : Limits, Derivatives, Integration, Implicit functions, continuousity, differentiation ,Extremum problems, Lagrange multipliers, Gradients, Surface integrals, Multi variables functions ,Multi variables Integrals,Complex variables ,Complex functions, Curves, Trajectory integrals & Vector analyse,Divergence,Rotor & word problems. Kind of question I can't answer : Economics,Combinatorics,infinite series & convergence ,Statistics & Probabilities .

Experience

1. I'm a team member of mathnerds (math site for answering questions) 2. I'm a team member in the Student's Union of the Technion, helping students who have problems in mathematics. 3. 2 years of experience as a math teacher in college. 4. I give free homework help for high school students in Mathematics & Physics. 5. I teach part time in collage the subjects : "Digital Signal Processing" , "Random Signals & Noise" , "Complex Functions".

Organizations
Hi-Tech company : GSM4VOIP ; job possition : Algorythm developer.

Education/Credentials
M.A in Mathematics & Bs.c in Electronics.

©2012 About.com, a part of The New York Times Company. All rights reserved.