How do you write #root3(x^-6)# with fractional exponent?

2 Answers
Mar 20, 2016

#x^-2#

Explanation:

Note that

#roota(x^b)=x^(a//b)#

Thus,

#root3(x^-6)=x^(-6//3)=x^-2#

Note that

#x^-2=1/x^2#

both of which are acceptable answers.

Mar 20, 2016

Very slight expansion on the process

#1/x^2 = x^(-2)#

Explanation:

Given:#" "root(3)(x^(-6))#

Consider the #x^(-6)# this is the same as #1/x^6#

Put it back into the root giving

#" "root(3)(1/x^6)#

This is the same as

#" " (root(3)(1))/(root(3)(x^6))#

But #x^6 = x^(2+2+2) = x^2xx x^2xx x^2 = (x^2)^3# giving

#" "(root(3)(1))/(root(3)((x^2)^3)) = 1/x^2#

#"'~~~~~~~~~~~~ Important Note ~~~~~~~~~~~~~~~~~~~~~~~"#

The key question is about the state being positive or negative.

Consider #root(3)(1)#: for 1 to be negative there would need to be an indicator in the starting point that complex numbers are involved. This is not the case so this question has no credence.

Consider the #x^2xx x^2xx x^2 #: if #x# where to be negative then each #x^2# would change it back to positive. So it is possible for #x<1#, that is, the source value could be either negative or positive.

However the given expression has been simplified such that it involves #x^2#. This automatically results in an outcome that is positive.

So it is correct to write the answer as positive. That is, we do not have negative #1/x^2#

Tony B