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

lkhkn
(edited 8 years ago)

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


Posted from TSR Mobile
Original post by Sam00
find 'a' if 'log(base a) = 3/2'

I am really stuck :frown:


log39=2 which is the same as 32=9log_3 9= 2 \ which\ is\ the\ same\ as\ 3^2=9
a=4


Posted from TSR Mobile
4 to the power of 3/2 = 8


Posted from TSR Mobile
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

loga8=32 which is the same as a32=8log_a 8=\dfrac{3}{2}\ which\ is\ the\ same\ as\ a^\frac{3}{2}=8
Original post by Truthseeker3


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


Posted from TSR Mobile


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


Posted from TSR Mobile
Original post by Truthseeker3


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


Posted from TSR Mobile


Full solutions are against TSR rules.
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..


Posted from TSR Mobile
They're against the rules? Oh didn't know


Posted from TSR Mobile
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
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..


Posted from TSR Mobile


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


Posted from TSR Mobile


now you know ^-^
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. :h:
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 :smile:

edit: a3/2 = (a3)1/2 Hence I got root a
(edited 8 years ago)
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 a32=8 a^\frac{3}{2}=8

Eliminate the powers. Square both sides: a3=64 a^3=64.

643=4\sqrt[3]{64}=4

Got it? :h:
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.
Original post by undercxver
So a32=8 a^\frac{3}{2}=8

Eliminate the powers. Square both sides: a3=64 a^3=64.

643=4\sqrt[3]{64}=4

Got it? :h:


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!
(edited 8 years ago)
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\LaTeX. :h:

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

It's fun but quite long quite to do for complicated maths. :yawn:
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\LaTeX. If you're doing maths at uni you'll probably come across it so it's good practice to use it on here :smile:.

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