Rangpur Secondary 2011/2

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Rangpur Secondary 2011/2

Unread post by Moon » Wed Feb 02, 2011 6:47 pm

Problem 2:
If $2<f<3$ and $-9<g<-1$, then what is the range of possible values of $fg$?
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Re: Rangpur Secondary 2011/2

Unread post by Tahmid Hasan » Wed Feb 02, 2011 7:25 pm

for the least value let's take $f$ as tends to $2$ and $g$ as tends to $-9$.so the least possible value of $fg$is tends to $-18$.let's do the same with the highest value.
the range is$-18<fg<-3$
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Re: Rangpur Secondary 2011/2

Unread post by tarek like math » Fri Apr 29, 2011 12:41 am

if f=3 and g=-9 then -27<fg<-3

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Re: Rangpur Secondary 2011/2

Unread post by Shifat » Fri Aug 05, 2011 3:10 am

-27<fg<-2..should be.

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Re: Rangpur Secondary 2011/2

Unread post by Ridwan Abrar » Sat Feb 01, 2014 12:48 am

Can anyone confirm which one is the correct answer?

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Re: Rangpur Secondary 2011/2

Unread post by *Mahi* » Sat Feb 01, 2014 8:10 pm

The correct answer is $-27 < fg < -2$
Just look out for what the highest and least value of $fg$ can be.
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