#ReCiPrOcAl-inequality

55 messages · Page 1 of 1 (latest)

stuck axle
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Will taking reciprocal necessarily change the inequality sign over here for all values of x?

exotic bloomBOT
stuck axle
magic cloud
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if $a>b$ and a,b have same sign (and not 0 ofc) then $\frac 1a < \frac 1b$

idle prairieBOT
magic cloud
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but if $a>b$ and a,b have different sign (and not 0 ofc) then $\frac 1a > \frac 1b$

idle prairieBOT
magic cloud
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like for eg 2 > -3

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so

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1/2 > -1/3

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but

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if 420>69 then 1/420 < 1/69

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wait 2/(x+1)>0 implies (x+1)/2 < 0 sus

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both are different regions

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it should’ve been x>-1

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i think the guy just did mistake

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@stuck axle

stuck axle
# stuck axle

2/x+1 can be -ve and positive ryt
So it's incorrect to take reciprocal

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Ryt

magic cloud
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no i mean its not incorrect to take reciprocal

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but

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it should be

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(x+1)/2>0

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if we’re excluding 1

stuck axle
magic cloud
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hm?

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x<2 is independent condition

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it is necessary but not sufficient

stuck axle
magic cloud
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-1<x<2

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thats what ur region is

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uhh did u get it?

stuck axle
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Wait

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I got smthg liek
X(x-1) /x+1 > 0

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From the log inequation

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Which implies x belongs to (-1, 0) U (1, ∞)

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And then x <2

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So (-1, 0) U (1, 2) so far

magic cloud
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seems alr

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lets check with wolfram tho

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,w log_(1/4)(2-x) > log_(1/4)(2/(x+1))

stuck axle
magic cloud
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yes

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what u got is corrext

stuck axle
magic cloud
magic cloud
stuck axle
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Ok ur making sense now

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Got it

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Tysm

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.close

exotic bloomBOT
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