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uri Group Title

Halp meh pliss, The number of positive values of x less than 360 degrees which satisfy the equation sin 1/2x =cos x is? a)0 b)1) c)2 d)3 e)4

  • one year ago
  • one year ago

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  1. saifoo.khan Group Title
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    You do math too? D:

    • one year ago
  2. hba Group Title
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    Mujhe bhi yaqeen nahi horaha :P

    • one year ago
  3. satellite73 Group Title
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    looks like there are two http://www.wolframalpha.com/input/?i=sin%28x%2F2%29%2Ccos%28x%29+domain+0..2pi

    • one year ago
  4. yrelhan4 Group Title
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    write cosx in terms of sin^2 x/2 and solve!

    • one year ago
  5. uri Group Title
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    1/2x=sin^2x/2 Right ?

    • one year ago
  6. yrelhan4 Group Title
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    cosx= 1-2sin^2 (x/2)

    • one year ago
  7. yrelhan4 Group Title
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    you get a quadratic.. solve for x..

    • one year ago
  8. uri Group Title
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    2sin^2(x/2)+cosx-1=0

    • one year ago
  9. yrelhan4 Group Title
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    2t^2 + t -1=0 where t=sin(x/2)

    • one year ago
  10. uri Group Title
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    Quad,breaking the middle term or completing the square method?

    • one year ago
  11. yrelhan4 Group Title
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    breaking the middle term.. you would get (2t-1)(t+1)=0 where t=sin(x/2)

    • one year ago
  12. uri Group Title
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    eh,2t-1=0=)t=1/2 t+1=0=)t=-1

    • one year ago
  13. yrelhan4 Group Title
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    yup!

    • one year ago
  14. uri Group Title
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    Sin(x/2)=1/2 Sin(x/2)=-1

    • one year ago
  15. yrelhan4 Group Title
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    so there would be 3 values of x/2 in 0 to 360.. 30,120,270. so x=60,240,540.. since you want from 0 to 360.. there would be 2 solns..

    • one year ago
  16. uri Group Title
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    it was Sin x/2

    • one year ago
  17. yrelhan4 Group Title
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    if sin(x/2) = 1/2 , what is x? 0>x>360

    • one year ago
  18. hba Group Title
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    Oh so, sin x/2 =cos x ?

    • one year ago
  19. yrelhan4 Group Title
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    1- sin^2(x/2)= cosx @hba

    • one year ago
  20. uri Group Title
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    em BOREEEEEED.

    • one year ago
  21. yrelhan4 Group Title
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    look.. let x/2=k .. sin(k)=1/2 --> k=30, 120.. --> x=60, 240

    • one year ago
  22. yrelhan4 Group Title
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    cosx= 1-2sin^2 (x/2) @hba missed the two..

    • one year ago
  23. yrelhan4 Group Title
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    thik hai? @uri

    • one year ago
  24. sirm3d Group Title
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    @yrelhan4 since \(\displaystyle 0 \leq x \leq 360\) then \(\displaystyle 0 \leq \frac{x}{2} \leq 180\)

    • one year ago
  25. sirm3d Group Title
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    now, \(\sin x/2 = 1/2\) therefore \(x/2=30, 150\) or \(x=60, 300\)

    • one year ago
  26. uri Group Title
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    Yrelhan GUESSSS WHAT?! I donyt undastand aaaanythang nd ima sho confuzzeld tooh,I caant eveen speel corractly. o.O

    • one year ago
  27. yrelhan4 Group Title
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    lol.. i am such a fool.. you are right! @sirm3d

    • one year ago
  28. uri Group Title
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    Wut iz the aaansweeer?! none of my option matches your answer!

    • one year ago
  29. yrelhan4 Group Title
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    i just wrotw150 value wrong, right? why am i a fool then? :P

    • one year ago
  30. sirm3d Group Title
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    the other equation, \(\sin x/2 = -1\) has no solution in \(0 \leq \frac{x}{2} \leq 180\)

    • one year ago
  31. yrelhan4 Group Title
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    @uri 2.. final!

    • one year ago
  32. uri Group Title
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    @sirm3d sinx/2=1 has no solution so we will leave it? xD

    • one year ago
  33. yrelhan4 Group Title
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    @uri its sin(x/2) = -1

    • one year ago
  34. uri Group Title
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    k.

    • one year ago
  35. sirm3d Group Title
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    @uri, just count the number of solutions: \(x=60^0,\;300^0\)

    • one year ago
  36. uri Group Title
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    @sirm3d 2 solutions?

    • one year ago
  37. sirm3d Group Title
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    yup. (C) 2

    • one year ago
  38. yrelhan4 Group Title
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    are kitni baar puchegi? @uri :P

    • one year ago
  39. uri Group Title
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    AMG THANKYOUUUUUUUUUUUUU!AMG THANKYOUU SOO MUCHHHHH!!!! :D

    • one year ago
  40. yrelhan4 Group Title
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    mera medal.. :'( .. aadha to maine solve kiya..

    • one year ago
  41. yrelhan4 Group Title
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    huh!

    • one year ago
  42. uri Group Title
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    You have 2 now :P

    • one year ago
  43. yrelhan4 Group Title
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    haha.. he's got 2 now too!

    • one year ago
  44. uri Group Title
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    Happy? :D

    • one year ago
  45. yrelhan4 Group Title
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    ha! yes.. :P

    • one year ago
  46. uri Group Title
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    Yw xD

    • one year ago
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