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Solve the Inequality

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Source: — Problem Solving |
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by tohellandback » Mon Aug 03, 2009 4:47 am
yeah u r right..
X > 1/X
for positive values of X
X^2>1
i.e.X>1

for negative values

X^2<1
i.e -1<X<0
The powers of two are bloody impolite!!
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by crejoc » Tue Aug 04, 2009 4:19 am
tohellandback wrote:yeah u r right..
for negative values
X^2<1
i.e -1<X<0
Can you please explain step by step arriving at the answer... That would be more helful.
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by tohellandback » Tue Aug 04, 2009 6:58 am
crejoc wrote:
tohellandback wrote:yeah u r right..
for negative values
X^2<1
i.e -1<X<0
Can you please explain step by step arriving at the answer... That would be more helful.
In an equality, when you multiply both sides with a positive value, the inequality sign remains unchanged.
but when you multiple both sides with a negative value, the inequality sign changes.
ex. 2<3, multiple both sides with 3
6<9, no change to the inequality "<"

now multiple both sides with '-3'
-6>-9, the inequality operator changed

so X > 1/X
if X>0
X^2>1. this is possible only for values X>1

when X is negative,
X>1/X
X^2<1, inequality changed

for negative values, this is pissible only when 0>X>-1
The powers of two are bloody impolite!!
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