Understanding (-27)^(2/3)
The expression (-27)^(2/3) represents a fractional exponent, which indicates both raising to a power and taking a root. Let's break it down:
Fractional Exponents
The fraction 2/3 signifies that we need to perform two operations:
- Cube root (3 in the denominator): Find the number that, when multiplied by itself three times, equals -27. This is -3 since (-3)(-3)(-3) = -27.
- Squaring (2 in the numerator): Square the result obtained in step 1, which is (-3)^2 = 9.
Calculation
Therefore, (-27)^(2/3) is calculated as follows:
- Cube root of -27: ∛(-27) = -3
- Square of -3: (-3)^2 = 9
Solution
Therefore, (-27)^(2/3) = 9.
Key Points
- Fractional exponents: a^(m/n) = (n√a)^m
- Cube root: The cube root of a number is the number that, when multiplied by itself three times, equals the original number.
- Negative base: When taking an odd root of a negative number, the result is negative.
- Even exponent: Squaring a negative number results in a positive number.