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Homework help!

  1. Oct 6, 2004 #1
    Can someone help me with this:cos^2x = 2cosxsinx?
    X E 0,360..
    I really haven`t understood this trigonomy stuff yet.. :yuck:
  2. jcsd
  3. Oct 6, 2004 #2

    matt grime

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    Did you see that sticky about posting homework?

    Hint: forget trig for now, and simplify

  4. Oct 6, 2004 #3
    Hi, Maria, I am Susan, :redface: What matt told you to do is something like this: :blushing:
    cosx(cosx-2sinx) =0
    cosx=0 OR tanx=1/2
    Last edited: Oct 6, 2004
  5. Oct 7, 2004 #4
    hi again

    Can you explain it to me a bit more?

    I need to understand the whole prosess, because I have to explain it to someone else on thursday.. I need 4 angles..
  6. Oct 7, 2004 #5


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    What you basically have is:

    [tex]a^2 = ab[/tex]

    You can wright this is:

    [tex]a^2 - ab = 0[/tex]

    [tex]a(a - b) = 0[/tex]

    This tells you that either [itex]a[/itex] is 0 or [itex]a - b[/itex] is 0, right? Well try and follow that procedure out with your trig functions.
  7. Oct 11, 2004 #6

    I got it right :smile: Thanks a lot
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