Solving x^(2/3)=4: Logarithms or What?

  • Thread starter Mozart
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    Logarithms
In summary, to solve for x in the equation x^(2/3)=4, you can rewrite it as x^2^(1/3)=4 and take the cube root of both sides to get x=4^(3/2)=8. This is a proper method and you got the correct answer.
  • #1
Mozart
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:frown: I don't remember how to do this x^(2/3)=4 solve for x Do you use logarithm or something?
 
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  • #2
I'm going to try my best to explain. Whenever you have a fractional exponent, that is another way of talking about a radical...


The "3" in the denominator of the fraction is what "root" your radical will be:

Ex. square root of 2 = 21/2
cubed root of 2 = 21/3

now, the numerator is what power "X" is going to be:

Ex. square root of 21 = 21/2
cubed root of 22 = 22/3

That should hopefully get you started in the right direction...
 
  • #3
After reading what you said I did the following.

wrote x^2 with the third root around it and made it equal 4.

I then took the square root of 4 to get rid of the square sign on x

I then cubed the 2 and got 8

After pugging the 8 into x^(2/3) I got 4

Please tell me I got the answer using a proper method and this isn't a cruel coincidence. Thanks by the way for the help!
 
Last edited:
  • #4
Mozart said:
After reading what you said I did the following.
wrote x^2 with the third root around it and made it equal 4.
I then took the square root of 4 to get rid of the square sign on x
I then cubed the 2 and got 8
After pugging the 8 into x^(2/3) I got 4
Please tell me I got the answer using a proper method and this isn't a cruel coincidence. Thanks by the way for the help!

sounds like you did it right.
 
  • #5
Thanks.
 

1. What is the first step in solving x^(2/3)=4?

The first step is to take the logarithm of both sides of the equation. This will help us eliminate the exponent and solve for x.

2. How do logarithms help us solve this equation?

Logarithms allow us to move the exponent from the left side of the equation to the right side, creating a simpler equation to solve.

3. Which logarithm should we use to solve this equation?

Since the base of the exponent is not specified, we can use any logarithm. However, it is most common to use the natural logarithm, ln, or the common logarithm, log, in these types of equations.

4. How do we solve for x once we have the logarithm of both sides?

Next, we use the properties of logarithms to simplify the equation. We can bring down the exponent as a coefficient and then solve for x using basic algebraic techniques.

5. Are there any restrictions on the solutions to this equation?

Yes, since the exponent is 2/3, we must remember to check for extraneous solutions. This means that we must make sure the solutions we obtain from solving the equation actually work when substituted back into the original equation.

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