- #1

- 9

- 0

e.g 3^x=9

(i know it is 2 but i would like to know the process for use with larger numbers).

Thankyou in advance

- Thread starter malco97
- Start date

- #1

- 9

- 0

e.g 3^x=9

(i know it is 2 but i would like to know the process for use with larger numbers).

Thankyou in advance

- #2

- 11

- 0

3^x=9

therefore

9=3^2

get the log base 3 of both sides

x=2

therefore

9=3^2

get the log base 3 of both sides

x=2

- #3

- 334

- 1

9 = 3^x

log 9 = log (3^x)

log 9 = x log 3

x = log9/log3 = 2

log can be to any base as long as they are the same. you will usually find base 10, or base e on your calculator. log base e is usually ln.

- #4

- 313

- 0

1) 3No, you used the fact x=2.

As long as we can think of the relationship between 3 and 9, we can solve this problem without using logarithm, like the one suggested by enslam.

here are more examples (solve for x)

2) 5

3) 4*5

4) 2

If you use Logarithm, in the step log9/log3, you need to know the fact that 9 = 3^2 too, unless you use a caculator.

- #5

HallsofIvy

Science Advisor

Homework Helper

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That's true as long as the "opposite" problem, finding the power, can be done easily- as long as the answer is an integer as in all of your examples.1) 3^{x}=9

As long as we can think of the relationship between 3 and 9, we can solve this problem without using logarithm, like the one suggested by enslam.

To solve, for example 3

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