Cos2x = 2 cos x sin x

  • Thread starter Maria
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  • #1
Maria

Main Question or Discussion Point

Can someone please help me with this one?

cos2x = 2 cos x sin x

I need to find 4 angles :uhh:
 

Answers and Replies

  • #2
Zurtex
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Within what range of x? And have you checked what I posted to this problem in the other thread?
 
  • #3
Maria
within the range of 0, 360
 
  • #4
Zurtex
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Well this is easily solvable as long as you remember these 2 identities:

[tex]\sin 2 \theta \equiv 2 \cos \theta \sin \theta[/tex]

and:

[tex]\tan \theta \equiv \frac{\sin \theta}{\cos \theta}[/tex]
 
  • #5
Maria
I got it right... :rofl:
 

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