My Math Forum  

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

Trigonometry Trigonometry Math Forum


Reply
 
LinkBack Thread Tools Display Modes
February 23rd, 2017, 05:04 AM   #1
Newbie
 
Joined: Nov 2016
From: London

Posts: 7
Thanks: 0

questions involving double angles

Hello everyone... again

I've been given a couple of questions and I have no flipping idea how to do them. The teacher has been over double angle identities with us but the following questions have left me stumped, even with all my notes and textbook out.

so here it is:

Solve the equation

$\sqrt{3}\cos2x-\sin x \cos x-1=0
\\
0\leq{x}\leq360^{\circ}$


The main problem here is that I'm not quite sure how to simplify it.

Thanks for reading! Looking forward to some enlightenment.

Last edited by skipjack; February 23rd, 2017 at 05:52 AM.
Alavanca11 is offline  
 
February 23rd, 2017, 05:58 AM   #2
Senior Member
 
romsek's Avatar
 
Joined: Sep 2015
From: CA

Posts: 1,206
Thanks: 613

Is it possibly $\dfrac{\sqrt{3}}{2}\cos(2x) - \sin(x)\cos(x)-1=0$?

Last edited by skipjack; February 23rd, 2017 at 06:11 AM.
romsek is offline  
February 23rd, 2017, 02:23 PM   #3
Global Moderator
 
Joined: May 2007

Posts: 6,216
Thanks: 493

Start with sinxcosx=(sin2x)/2. Try solving for 2x.
mathman is offline  
Reply

  My Math Forum > High School Math Forum > Trigonometry

Tags
angles, double, involving, questions



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can anyone help me solve these questions? modulo questions vickyc95 Number Theory 4 May 24th, 2016 07:20 PM
Probability Questions Involving 64 Numbers EvanJ Advanced Statistics 0 December 5th, 2013 06:08 PM
Sum of three angles mathbalarka Algebra 2 April 19th, 2013 09:42 AM
3D Angles Philosophaie Physics 0 August 17th, 2008 10:31 PM
Two Questions Involving Algebra, Quadratics and Geometry distinctly_dutch Geometry 2 April 17th, 2008 05:41 PM





Copyright © 2017 My Math Forum. All rights reserved.