X^-2 compared to (-x)^-2 are both the same
X^-1 compared to (-X)^-1 are not
X^-2 is
1/X^2
1/X & -1/X
for all values X<0
the inequality becomes
1/X^2 < 1/X
and
assume X to be -1
1/(-1)^2 = 1
1/-1 = -1
1< -1 is false so the inequality is not valid.
2007-01-04 10:14:53
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answer #1
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answered by beanie_boy_007 3
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Is x^-2 < x^-1 for any negative value(s) of x? Why or why not?
= 1/x^2 < 1/x
The first term is always positive for all x, however
the second term is positive when x is positive and negative when x is negative.
Therefore the inequality does not hold for x < 0.
A positive number cannot be less than a negative number.
2007-01-04 18:25:34
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answer #2
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answered by ironduke8159 7
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x^(-2) < x^(-1)
First, convert these into having positive exponents.
1/x^2 < 1/x
Multiply both sides by x. Note that x is a negative value (given by the question), so this will switch the sign.
x/x^2 > 1
Now, we can cancel the left hand side.
1/x > 1
Multiply both sides by x; this will switch the sign (for multiplying by the negative number)
1 < x, which means x > 1. This contradicts the fact that x is a negative value, so this is never true.
2007-01-04 18:56:42
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answer #3
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answered by Puggy 7
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No
If x< 0
then x^(-1) < 0
However x² > 0 so x^(-2) > 0
Therefore x^(-2) > x^(-1) for all x < 0
2007-01-04 18:16:04
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answer #4
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answered by Wal C 6
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graph it and see if the negative values of
x^-2 are less than x^-1
2007-01-04 18:11:08
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answer #5
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answered by m0rph0s1s 2
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x^-2 = 1/ (x^2) > 0
Where as
x^-1 = 1 / x < 0 (for x<0)
So the statement is false
2007-01-04 18:14:57
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answer #6
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answered by xxxxnguyen 2
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(1/x)^2 < (1/x)
no
because
(1/-5)^2= a postive number
(1/-5) = a negative number
so if x is negative
x^-2 > x^-1
2007-01-04 18:14:41
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answer #7
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answered by no man 2
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let x=-3
(-3)^-2=1/(-3)^2=1/9
x^-1=1/x=1/-3
x^-2>x^-1
2007-01-04 18:15:37
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answer #8
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answered by raj 7
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