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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 20,927

#1. Evaluate

.#2. If

, find the value of x.#3. Evaluate :

.#4. Simpligy:-

#5. Find the value of x which satisfies the relation

#6. Simplify:-

#7. If

, find the number of digits in .It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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**glenn101****Member**- Registered: 2008-04-02
- Posts: 108

1.

7^x=1/343

7^x=7^-3

x=-3

2.

root8^x=10/3

x=2log(10/3)

-------------

3log(2)

x=1.12

3. I'm assuming you use a calculator, I've never encountered a question like that non-tech.

=2/3

Thats all I got so far:)

"If your going through hell, keep going."

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 20,927

glenn101,

Solution to the first problem is correct, Good!

Here I have solved two problems for you:-

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 20,927

I shall do #2 and #3 for you, glenn101!

#2. If

, find the value of x.x = 32.

#3. Evaluate :

.=

=

=

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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**glenn101****Member**- Registered: 2008-04-02
- Posts: 108

Thanks for the answers ganesh!

I havn't been taught those sorts of logs before, with surds and same bases.

Looks interesting.

Thanks again

"If your going through hell, keep going."

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**careless25****Real Member**- Registered: 2008-07-24
- Posts: 559

glenn have you been taught change of base formula yet?

For number #3 ganesh used that.

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**glenn101****Member**- Registered: 2008-04-02
- Posts: 108

and no I havn't careless, I've only been taught how to deal with same bases, nothing advanced. Next year we deal with e and I'm guessing we will also be taught the change of base formula.

"If your going through hell, keep going."

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**ganesh****Moderator**- Registered: 2005-06-28
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glenn101,

The base change formula is very useful.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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**careless25****Real Member**- Registered: 2008-07-24
- Posts: 559

Ganesh i havent been taught that far yet... but for me the base change formula is using base 10 so we can use calculators...

so i always do this:

log 25 (100) = log 10 (100) * log 10 (25)

so always base 10.

but i can see what you mean by that formula and example.

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**glenn101****Member**- Registered: 2008-04-02
- Posts: 108

Hmm that formula looks straightforward and useful!

thanks for that ganesh!

"If your going through hell, keep going."

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 20,927

Its a pleasure helping you with logarithms,

logs are such an important tool in calculations!

For my Practical Final-I at University, I had to find the Young's Modulus and this would have been extremely difficult without logarithms or a scientific calculator! We were not allowed to use calculators!

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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**careless25****Real Member**- Registered: 2008-07-24
- Posts: 559

Yup my pre-calculus class is heading there...NO CALCULATORS!

except the one in my head!

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**glenn101****Member**- Registered: 2008-04-02
- Posts: 108

Yeah, logs have always been my favorite topic, its easy for me to understand.

Then comes calculus and trig.:D

"If your going through hell, keep going."

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