How Do You Handle Exponents Inside a Radical?

  • Thread starter Thread starter Cornraker
  • Start date Start date
  • Tags Tags
    Exponents
AI Thread Summary
To simplify exponents inside a radical, divide the exponents by the index of the radical. For the expression ∛(x^6 y^4), it can be rewritten as ∛(x^6) ∛(y^4). This leads to the simplification x^2 y^(4/3), which can also be expressed as x^2 y y^(1/3). The radical notation represents an inverted exponent, allowing for this simplification process. Understanding this method is crucial for handling radicals with exponents effectively.
Cornraker
Messages
24
Reaction score
0

Homework Statement



When there are exponents in a radicand as shown below, do i just divide them out?

Homework Equations



∛(x^6 y^4 )

The Attempt at a Solution



x^2 y^4 ?
 
Physics news on Phys.org
Cornraker said:

Homework Statement



When there are exponents in a radicand as shown below, do i just divide them out?

Homework Equations



∛(x^6 y^4 )

The Attempt at a Solution



x^2 y^4 ?

You are asking about
\sqrt[3]{x^6 y^4}​

Given your bracketing the y4 is inside the cube root as well. Note that you can write
\sqrt[3]{x^6 y^4} = \sqrt[3]{x^6} \sqrt[3]{y^4}​
 
But to simplify it further to i divide the exponents of the variables by the index of the radical? I'm sorry if my terminology is bad and if my equations aren't right I'm new to this forum so I'm trying to get it right.
 
Cornraker said:
But to simplify it further to i divide the exponents of the variables by the index of the radical? I'm sorry if my terminology is bad and if my equations aren't right I'm new to this forum so I'm trying to get it right.

Yes. Your original answer only divided one of the exponents, but from the brackets it appears both x^6 and y^4 are inside the radical. The radical notion is just another way of writing an inverted exponent. That is
\sqrt[n]{a} = a^{1/n}​
 
Cornraker said:
But to simplify it further to i divide the exponents of the variables by the index of the radical? I'm sorry if my terminology is bad and if my equations aren't right I'm new to this forum so I'm trying to get it right.
Notice that
\sqrt[3]{x^6y^4}= \sqrt[3]{(x^3)(x^3)(y^3)(y)}= \sqrt[3]{x^3}\sqrt[3]{x^3}\sqrt[3]{y^3}\sqrt[3]{y}= (x)(x)(y)(\sqrt[3]{y})= x^2y\sqrt[3]{y}

Yes, that is the same as (x^6y^4)^{1/3}= x^{6/3}y^{4/3}= x^2y^{1+ 1/3}= x^2yy^{1/3}
 
I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Essentially I just have this problem that I'm stuck on, on a sheet about complex numbers: Show that, for ##|r|<1,## $$1+r\cos(x)+r^2\cos(2x)+r^3\cos(3x)...=\frac{1-r\cos(x)}{1-2r\cos(x)+r^2}$$ My first thought was to express it as a geometric series, where the real part of the sum of the series would be the series you see above: $$1+re^{ix}+r^2e^{2ix}+r^3e^{3ix}...$$ The sum of this series is just: $$\frac{(re^{ix})^n-1}{re^{ix} - 1}$$ I'm having some trouble trying to figure out what to...
Back
Top