176k views
1 vote
Compute [(-8)^{-2/3}.

1 Answer

0 votes

Final answer:

To compute (-8)^{-2/3}, find the cube root of 8, square it, and then take the reciprocal due to the negative exponent. Thus, the result of this expression is 1/4.

Step-by-step explanation:

To compute the expression (-8)^{-2/3}, we can break it down into two steps. First, the exponent -2/3 means we take the cube root and then square it. Secondly, because the exponent is negative, we will take the reciprocal of the result.

  • Find the cube root of 8, which is 2 (Notice that we take the positive cube root of a positive number even though our base is negative; we will consider the negative sign after).
  • Since the base is negative and the exponent -2/3 suggests an even power, the overall result will be positive. So, we have the cube root of negative eight being negative two (-2).
  • Square the result of the cube root: (-2)^2 = 4.
  • Because the exponent is negative, we take the reciprocal of 4, which is ⅓.

Therefore, (-8)^{-2/3} = ⅓.

User Brock Gion
by
7.8k points