Simple logarithm question I am really stuck on: Could someone please help? Watch

Sam00
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Truthseeker3
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What does logs do and mean? You can rewrite your answer


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thefatone
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(Original post by Sam00)
find 'a' if 'log(base a) = 3/2'

I am really stuck
log_3 9= 2  \ which\ is\ the\ same\ as\ 3^2=9
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Truthseeker3
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a=4


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Truthseeker3
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4 to the power of 3/2 = 8


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thefatone
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(Original post by Sam00)
Sorry I don't understand what you mean

The question I am revising is:

log(base a) of 8 = 3/2 (or 1.5)

An I need to find the value of a
ok so this is what you have right now

log_a 8=\dfrac{3}{2}\ which\ is\ the\ same\ as\ a^\frac{3}{2}=8
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thefatone
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(Original post by Truthseeker3)
a=4


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(Original post by Truthseeker3)
4 to the power of 3/2 = 8


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hey! we're supposed to help the arrive at the answer not just give them the answer >.>
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Truthseeker3
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Sam should know that rule thefatone, if he has learned logs


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undercxver
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(Original post by Truthseeker3)
a=4


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(Original post by Truthseeker3)
4 to the power of 3/2 = 8


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Full solutions are against TSR rules.
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Truthseeker3
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We don't need to baby step anyone. People should struggle and learn it, it's not that hard, anyone can do it, he needs to go and learn logs then..


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Truthseeker3
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They're against the rules? Oh didn't know


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thefatone
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(Original post by Sam00)
So would I then have to root each side to get the value of a?
no you have to cube root first the square
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thefatone
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(Original post by undercxver)
Full solutions are against TSR rules.
(Original post by Truthseeker3)
We don't need to baby step anyone. People should struggle and learn it, it's not that hard, anyone can do it, he needs to go and learn logs then..


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(Original post by Truthseeker3)
They're against the rules? Oh didn't know


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now you know ^-^
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undercxver
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(Original post by Sam00)
so if a^3/2 = 8

would I do 3/2√8 = a?

therefore 3/2√8 = 4?
You might wanna watch this video for some help on Logarithms.
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NadeemKha_Arab
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(Original post by Sam00)
so if a^3/2 = 8

would I do 3/2√8 = a?

therefore 3/2√8 = 4?
You've got:

a3/2= 8

Do you agree that:

√(a3) = 8

Therefore square both sides:

a3 = 64

I hope you can get the last bit

edit: a3/2 = (a3)1/2 Hence I got root a
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undercxver
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(Original post by Sam00)
I have just watched the 2nd one and it makes sense that:

log(basea)x = p -----> a^p = x

therefore as I have log(basea)8 = 3/2 ------> a^3/2 = 8

I am not sure where to go from here as it doesn't explain

So  a^\frac{3}{2}=8

Eliminate the powers. Square both sides:  a^3=64.

\sqrt[3]{64}=4

Got it?
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NadeemKha_Arab
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(Original post by Sam00)
Ok so is a3/2= the same as √(a3) so the root side gets rid of the denominator in the power fraction?
As, rules of indices (or rules of order) says:

x1/2 = √x

x1/3 = 3√x

etc..

In your question I split the 3/2 into 3 x 1/2.
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NadeemKha_Arab
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(Original post by undercxver)
So  a^\frac{3}{2}=8

Eliminate the powers. Square both sides:  a^3=64.

\sqrt[3]{64}=4

Got it?
How do you get all those roots and stuff on here? This is the first time I've done maths on TSR and I've only found the x2 button and I really enjoy using it now ahahah!
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undercxver
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(Original post by NadeemKha_Arab)
How do you get all those roots and stuff on here? This is the first time I've done maths on TSR and I've only found the x2 button and I'm really enjoy using it now ahahah!
Haha, this is called \LaTeX.

If you want help with this check out the \LaTeX help page.

It's fun but quite long quite to do for complicated maths. :yawn:
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Dilzo999
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(Original post by NadeemKha_Arab)
How do you get all those roots and stuff on here? This is the first time I've done maths on TSR and I've only found the x2 button and I really enjoy using it now ahahah!
Yup \LaTeX. If you're doing maths at uni you'll probably come across it so it's good practice to use it on here .
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