My Math Forum  

Go Back   My Math Forum > High School Math Forum > Trigonometry

Trigonometry Trigonometry Math Forum


Reply
 
LinkBack Thread Tools Display Modes
November 14th, 2017, 03:21 AM   #1
Newbie
 
Joined: Nov 2017
From: Dresden, Saxony, Germany

Posts: 2
Thanks: 0

Question Trigonometrical Equation, don't know how to simplify it

Hi everyone.

I have an expression
-cos(f)*(sin(g)*cos(m)*cos(l) + sin(g)*sin(m)*sin(l)) + cos(g)*sin(f)

which is equal to
cos(g)*sin(f) - cos(f)*sin(g)*cos(l - m)

according to Wolfram Alpha's CAS.

I have no clue how to get there.

Thanks in advance,

Peter

Last edited by skipjack; November 14th, 2017 at 04:09 AM.
trustMeImAnEngineer is offline  
 
November 14th, 2017, 04:08 AM   #2
Global Moderator
 
Joined: Dec 2006

Posts: 19,527
Thanks: 1750

-cos(f)*(sin(g)*cos(m)*cos(l) + sin(g)*sin(m)*sin(l))
= -sin(g)cos(f)(cos(m)cos(l) + sin(m)sin(l))
= -sin(g)cos(f)cos(l - m)

Now add cos(g)sin(f) to both sides.
skipjack is offline  
November 16th, 2017, 02:08 AM   #3
Newbie
 
Joined: Nov 2017
From: Dresden, Saxony, Germany

Posts: 2
Thanks: 0

Thank you so much skipjack
trustMeImAnEngineer is offline  
Reply

  My Math Forum > High School Math Forum > Trigonometry

Tags
equation, simplify, trigonometrical



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Differentiation of Trigonometrical Functions Lucas Webb Calculus 4 March 2nd, 2016 02:13 AM
Differentiation of Trigonometrical Functions Lucas Webb Calculus 4 February 29th, 2016 06:14 PM
trigonometrical fallacy Vale Trigonometry 3 January 7th, 2014 11:25 PM
Trigonometrical trouble azelio Algebra 3 October 24th, 2010 05:45 PM
Trigonometrical Problem (difficult) co461 Algebra 4 April 25th, 2008 05:36 AM





Copyright © 2018 My Math Forum. All rights reserved.