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LilVeroDez13

  • 3 years ago

Counterexample problem.. jus want to know if its right. Thanks!

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  1. LilVeroDez13
    • 3 years ago
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    x = 1

  2. Emah
    • 3 years ago
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    that looks right:)

  3. LilVeroDez13
    • 3 years ago
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    thanks! :)

  4. TuringTest
    • 3 years ago
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    it's not right

  5. TuringTest
    • 3 years ago
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    what would happen if you plugged in x=1 ? you get\[x^2\ge1\implies x\ge1\]\[1^2\ge1\implies1\ge1\]where is the falsehood here?

  6. myininaya
    • 3 years ago
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    I agree with @TuringTest 1 does equal 1.

  7. LilVeroDez13
    • 3 years ago
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    ohh yeah.. it wouldnt b false.

  8. Emah
    • 3 years ago
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    but its saying OR equal to

  9. TuringTest
    • 3 years ago
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    and it is equal, so it's true

  10. LilVeroDez13
    • 3 years ago
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    @Emah yeahh thats true.. i dont see another answer that works

  11. TuringTest
    • 3 years ago
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    try each one individually

  12. Emah
    • 3 years ago
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    oh oops i sdidnt see the part that said couterexample:( sorry

  13. LilVeroDez13
    • 3 years ago
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    ohh its okk

  14. TuringTest
    • 3 years ago
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    what do you get when you plug in x=2\[x^2\ge1\]\[x\ge1\]are both still true?

  15. LilVeroDez13
    • 3 years ago
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    i get that its false

  16. TuringTest
    • 3 years ago
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    which part is false?

  17. LilVeroDez13
    • 3 years ago
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    first part

  18. TuringTest
    • 3 years ago
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    \[2^2\ge1\]is not true you say?

  19. LilVeroDez13
    • 3 years ago
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    Im confused

  20. TuringTest
    • 3 years ago
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    we need to find an example where the first part is true, and the second part is false to disprove the statement

  21. TuringTest
    • 3 years ago
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    \[2^2=4\]and four is greater than one, so \[x^2\ge1\]is true for x=2

  22. TuringTest
    • 3 years ago
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    what about the other part, is\[2\ge1\]?

  23. LilVeroDez13
    • 3 years ago
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    its true because 2 is greater tha 1

  24. TuringTest
    • 3 years ago
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    right, so both statements are true for x=2, so this is not a counterexample

  25. TuringTest
    • 3 years ago
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    what about for x=-3 is\[x^2\ge1\]and is\[x\ge1\]?

  26. LilVeroDez13
    • 3 years ago
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    first one is 9 > 1 (true) second one is 3 > 1 (true too)

  27. LilVeroDez13
    • 3 years ago
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    so than its 1/4 (:

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