IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => IGCSE/ GCSE => Math => Topic started by: **!!superexcited!!!** on October 27, 2009, 10:43:05 am
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Can any1 plz solve d question attatched......:
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n=5/3
u hav to use log, thats how i did it....
i cant explain...
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32^(1/n) = 8
Using log,
(1/n)lg32 = lg8
(1/n) = lg8/lg32
n = 1/(lg8/lg32)
= 5/3
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n=5/3
u hav to use log, thats how i did it....
i cant explain...
hey the dude... Can u pleeeeeez type in the operation u use for log.... :)
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Thanks... :)
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:)
32^(1/n) = 8
Using log,
(1/n)lg32 = lg8
(1/n) = lg8/lg32
n = 1/(lg8/lg32)
= 5/3
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Hey do u hv to use log for quests like 32 raised to n = 2
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32 = 2^5
so 32^2 = 2^(5*2)
= 2^10
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:)
32 = 2^5
so 32^2 = 2^(5*2)
= 2^10
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32 = 2^5
so 32^2 = 2^(5*2)
= 2^10
Hey wait a min, I dint get that.. :(
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this is d quest...
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That is what i get.
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32 = 2^5
2^5n = 2
5n = 1
n = 1/5
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32 = 2^5
2^5n = 2
5n = 1
n = 1/5
From wer do u get 5?? Can we use log for this question???
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Cant see anythin... :(
That is what i get.
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see ...its like 2 to the power 5 is 32 right? so 32^n=2^5...so n=5...thats it...got it???
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For the 1st 1..
U don't really ahve to use log.. I just realised that..
It's pretty simple in fact
32 = 2^5
n Root of 32 = 32^(1/n)
Implying that 2^(5/n) = 8
Now, 8 = 2^3
=> 32^(1/n) = 2^(5/n) = 8 = 2^3
2^(5/n) = 8 = 2^3
=>> Equating the powers of 2
5/n = 3
n = 5/3
This method is useful if you are not allowed the use of a calculator
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From wer do u get 5?? Can we use log for this question???
how will u express 4 as 2x
ofcourse it is 22 which is equal to 4
samething for 32
2what? = 32
2^5 = 32
yes u can use log this way
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2x = 32
log232 = x
in ur calculator do this
(log 32)/ (log 2) to get the answer 5
follow the rest of the steps for solving
@nits94 - n is not equal to 5...u have to express 32 as 2^5 adn then do it
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From wer do u get 5?? Can we use log for this question???
this question does not expect log, though you can use...
32n = 2
in this case u have to rearrange 32n in such that its base is 2.
so 32 can be written as 25.
so now
25n = 2
now as the base are same, the power has to be the same, therefore 5n = 1
now solve for n and the answer is 0.2 or 1/5
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this is d quest...
the above was the answer for the quoted one..
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For the 1st 1..
U don't really ahve to use log.. I just realised that..
It's pretty simple in fact
32 = 2^5
n Root of 32 = 32^(1/n)
Implying that 2^(5/n) = 8
Now, 8 = 2^3
=> 32^(1/n) = 2^(5/n) = 8 = 2^3
2^(5/n) = 8 = 2^3
=>> Equating the powers of 2
5/n = 3
n = 5/3
This method is useful if you are not allowed the use of a calculator
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:)Thanx
see ...its like 2 to the power 5 is 32 right? so 32^n=2^5...so n=5...thats it...got it???
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:)Thanx
thats a rong method..
n is not equal to 5
look at the method i sameer, deep and i gave above..
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m confused...i usually get it as n=5...n my teacher says its right...is it in any of the past papers???
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:) Thank u guys...Ur solutions really helped me...
Thanx again :)
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yeah.. anywayz gtg study now... Talk to you later bye :)
m confused...i usually get it as n=5...n my teacher says its right...is it in any of the past papers???
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o ya ..u all r right...its llike
32^n=2
so 2^5n=2^1
that is 5n=1
n=1/5
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Hey guys sry to disturb ull but 1 more :) ....plz help
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square both sides..
32 = 2^2p
5 = 2p
p = 2.5
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hey adi...shudn't it be like this???
root 32 = sp
=>21/5 = 2p
=>p = 1/5
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root 32= 321/2
u know 25=32
so
so 25 ^1/2=2^p
so 2^5/2 = 2^p
p=5/2
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:)Thanx i really get confused in these type of sums just wanted to confirm working...If possible can u do this one too...THANX a loooooot.... :)
square both sides..
32 = 2^2p
5 = 2p
p = 2.5
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:) :)
root 32= 321/2
u know 25=32
so
so 25 ^1/2=2^p
so 2^5/2 = 2^p
p=5/2
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hey adi...shudn't it be like this???
root 32 = sp
=>21/5 = 2p
=>p = 1/5
oohhh sorry my fault...it shud be 25/2
just forgot it in d hurry
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:)Thanx i really get confused in these type of sums just wanted to confirm working...If possible can u do this one too...THANX a loooooot.... :)
I have attached a file... See it.