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Math Help - solving inequalities

  1. #1
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    solving inequalities

    when solving an inequality and you have to take the square root of both sides, what is the rule for the changing of the inequality sign?

    if the number was between 0 and 1, then the sign would need changing, but if it were greater than 1, it wouldnt

    same goes for 0 and -1.

    for example:

    -9 < 16x^2

    that turns into: 3i < 4x
    but im unsure because the rules would differ for the above mentioned numbers.

    helppp
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    Quote Originally Posted by justahengin87 View Post
    when solving an inequality and you have to take the square root of both sides, what is the rule for the changing of the inequality sign?

    if the number was between 0 and 1, then the sign would need changing, but if it were greater than 1, it wouldnt

    same goes for 0 and -1.

    for example:

    -9 < 16x^2

    that turns into: 3i < 4x
    but im unsure because the rules would differ for the above mentioned numbers.

    helppp
    This doesn't make any sense since complex numbers can't be ordered...
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  3. #3
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    bad example, but what is the ruling?
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    Quote Originally Posted by justahengin87 View Post
    when solving an inequality and you have to take the square root of both sides, what is the rule for the changing of the inequality sign?

    if the number was between 0 and 1, then the sign would need changing, but if it were greater than 1, it wouldnt

    same goes for 0 and -1.

    for example:

    -9 < 16x^2

    that turns into: 3i < 4x
    but im unsure because the rules would differ for the above mentioned numbers.

    helppp
    If you are taking the square root of both sides of an inequality, you have to make use of the fact that \sqrt{x^2} = |x|.
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