My Math Forum  

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

Algebra Pre-Algebra and Basic Algebra Math Forum


Reply
 
LinkBack Thread Tools Display Modes
March 11th, 2011, 09:33 AM   #1
Member
 
Joined: Feb 2009

Posts: 54
Thanks: 0

Solve equation


All Ive got so far is
Valar30 is offline  
 
March 11th, 2011, 10:25 AM   #2
Global Moderator
 
The Chaz's Avatar
 
Joined: Nov 2009
From: Northwest Arkansas

Posts: 2,766
Thanks: 4

Re: Solve equation

So far, so good.
Now replace sin^2(x) with 1 - cos^2(x) in both places, and you should get a quadratic equation "in cos(x)".

ie, if you sub U = cos(x), you'll be able to rewrite as
aU^2 + bU + c = 0 and solve by usual methods.
The Chaz is offline  
March 11th, 2011, 06:47 PM   #3
Senior Member
 
Joined: Apr 2007

Posts: 2,140
Thanks: 0

Tank271, this should be very easy to solve if you know the trigonometric identities cos 2x = cos²x - sin²x and sin²x + cos²x = 1.
johnny is offline  
Reply

  My Math Forum > High School Math Forum > Algebra

Tags
equation, solve



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Solve the Equation for X Shamieh Algebra 6 May 21st, 2013 09:46 PM
solve equation mmmmxxx Algebra 3 September 4th, 2012 06:22 PM
Solve the equation... boomer029 Algebra 8 March 17th, 2012 05:09 PM
Solve the equation indicated ishoothigh Algebra 1 December 14th, 2011 08:09 AM
solve this equation for x sagelady Calculus 2 July 24th, 2011 08:35 PM





Copyright © 2018 My Math Forum. All rights reserved.