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Algebra and sqrs n sqrrt

  1. May 4, 2008 #1
    my problem is this: √(4800)=√((80cos ̂)^2+(80sin ̂)^2)
    pretty simple i no but i still keep making mistakes somewhere.
    i can get it down to: 4800/6400=(cos ̂)^2 + (sin ̂)^2
    but then i get a little stuck.
    by the way ̂=thetre=unkown angle.
    good luck
    i need it.
  2. jcsd
  3. May 4, 2008 #2
    It's false.... sin2(x) + cos2(x) = 1 for all values of x and 4800/6400 is not equal to 1, thus the equation is simply false.
  4. May 4, 2008 #3
    yea i figured that out just before. oops. mybad. but how could you rearange a similar equation so that it equalled thetre.
    im not very intelligent if u havent already noticed.
    no wait scratch that. how could u rearrange the equation x=(cos thetre)^2 + (sin thetre)^2
    even though my original numbers were incorrect.
    Last edited: May 4, 2008
  5. May 5, 2008 #4
    in that situation x must be 1, it cannot have any other value if that is to be a true statement.
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