cube root of (-89)

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cube root of (-89)

by uptowngirl92 » Tue Nov 03, 2009 5:23 pm
The value of cube root of (-89) is..?

Between -9 and 10
Between -8 and -9
Between -4 and 5
Between -3 and 4
Undefined

...................

[spoiler=]Is'nt the root of any negative number undefined?[/spoiler]
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Re: cube root of (-89)

by xcusemeplz2009 » Tue Nov 03, 2009 7:14 pm
uptowngirl92 wrote:The value of cube root of (-89) is..?

Between -9 and 10
Between -8 and -9
Between -4 and 5
Between -3 and 4
Undefined

...................

[spoiler=]Is'nt the root of any negative number undefined?[/spoiler]
IMHO
Sqrt of a -ve no. is imaginery,
but here its cube root
for this one i hope u have a typo in choice a) it should be -10

OA pls
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by NikolayZ » Wed Nov 04, 2009 6:29 am
Well, still we can answer this question.

-89 is negative, hence the number^3=-89 must be negative too.
(-3)^3=-27
(-4)^3=-64
(-5)^3=-125,
Hence the cube root of (-89) must be in (-4;-5), the only segment that must include this number is A: (-9;10)

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by sanjana » Wed Nov 04, 2009 9:16 am
The answer is between -4 and -5.

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by heshamelaziry » Wed Nov 04, 2009 10:38 am
IMO -4, 5