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No stupid answers... college level algebra.

2007-01-04 10:08:56 · 8 answers · asked by girl_pink 1 in Science & Mathematics Mathematics

8 answers

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 · answer #1 · answered by beanie_boy_007 3 · 0 0

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 · answer #2 · answered by ironduke8159 7 · 0 0

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 · answer #3 · answered by Puggy 7 · 0 0

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 · answer #4 · answered by Wal C 6 · 0 0

graph it and see if the negative values of
x^-2 are less than x^-1

2007-01-04 18:11:08 · answer #5 · answered by m0rph0s1s 2 · 0 0

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 · answer #6 · answered by xxxxnguyen 2 · 0 0

(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 · answer #7 · answered by no man 2 · 1 0

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 · answer #8 · answered by raj 7 · 0 0

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