N00b here and i got a question (logarithms)

  • Thread starter mathdummy
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  • #1
mathdummy

Main Question or Discussion Point

Okay.
"Solve the exponential equation with base a algebraically. Approximate the result to three decimal places."

3^2x=80

(fyi, the answer is ln80/2ln3 = 1.994)

Don't understand how to solve, please help!
 

Answers and Replies

  • #2
jcsd
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As you already have the answer and you want to understand the question, I think it's okay to take you through it step-by-step:

32x = 80

take the natural logarithm of both sides:

ln 32x = ln 80

use the rule ln xy = yln x:

2xln 3 = ln 80

2x = ln 80/ln 3

x = ln 80/2ln 3
 
  • #3
mathdummy
Ah. Thanks alot! For future reference, how can i show the numbers being squared in the corner and small like you were able to
 
  • #4
jcsd
Science Advisor
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