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elegant11

Find the values of x for which the equation cos x = –1 is true. Let k represent an integer.

  • one year ago
  • one year ago

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  1. jkasdhk
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    x = (cos)^-1 (-1)

    • one year ago
  2. elegant11
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    these are the answer choices 2pik pi/2 + 2k pi + 2pik 3pi/2+ 2pik

    • one year ago
  3. jkasdhk
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    isn't there k in the equation? which we're supposing as an integer?

    • one year ago
  4. elegant11
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    i have no idea. i don't even know where to begin :(

    • one year ago
  5. jkasdhk
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    hold on.. and check the question again if it is the same u've written?

    • one year ago
  6. elegant11
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    Find the values of x for which the equation cos x = –1 is true. Let k represent an integer.

    • one year ago
  7. jkasdhk
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    I'm gonna go now, will tell u after solving..

    • one year ago
  8. elegant11
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    thanks

    • one year ago
  9. jkasdhk
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    Well when is cosx = -1 the first time in the circle? At π (because x=180 degrees)... right? So now when does it occur again, well it doesnt happen again until we go around in a full circle. So another 2π and this will happen indefinitely for any integer k. So the answer is: π + 2πk

    • one year ago
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