Math Problem Statement

how do you solve fractional indicies

Solution

To solve expressions with fractional indices (exponents), you follow a method that connects the fractional exponent with roots and powers. Here's the general approach:

General Formula:

amn=(an)m=(am)1na^{\frac{m}{n}} = \left( \sqrt[n]{a} \right)^m = \left( a^m \right)^{\frac{1}{n}} Where:

  • aa is the base,
  • mm is the numerator of the fraction (which represents the power),
  • nn is the denominator (which represents the root).

Steps to Solve:

  1. Rewrite the fractional exponent using the rule: amn=amna^{\frac{m}{n}} = \sqrt[n]{a^m} or amn=(an)ma^{\frac{m}{n}} = \left( \sqrt[n]{a} \right)^m.

    • The denominator nn corresponds to the root of the number aa.
    • The numerator mm corresponds to the power of the number aa.
  2. Simplify the root: Take the nn-th root of the base first.

  3. Apply the power: Once you’ve found the root, raise it to the power mm.

Example 1: Solve 163216^{\frac{3}{2}}

  • Step 1: Rewrite the expression. 1632=(16)316^{\frac{3}{2}} = \left( \sqrt{16} \right)^3
  • Step 2: Find the square root of 16 (since the denominator is 2). 16=4\sqrt{16} = 4
  • Step 3: Raise the result to the power of 3 (since the numerator is 3). 43=644^3 = 64 So, 1632=6416^{\frac{3}{2}} = 64.

Example 2: Solve 272327^{\frac{2}{3}}

  • Step 1: Rewrite the expression. 2723=(273)227^{\frac{2}{3}} = \left( \sqrt[3]{27} \right)^2
  • Step 2: Find the cube root of 27 (since the denominator is 3). 273=3\sqrt[3]{27} = 3
  • Step 3: Raise the result to the power of 2 (since the numerator is 2). 32=93^2 = 9 So, 2723=927^{\frac{2}{3}} = 9.

Summary:

  • Fractional indices are essentially combinations of roots and powers.
  • The denominator represents the root and the numerator represents the power.

Would you like to go over more details or examples? Here are some related questions to explore:

  1. How do you simplify xmnx^{\frac{m}{n}} when xx is negative?
  2. How do you solve equations with fractional indices?
  3. Can fractional indices result in irrational numbers?
  4. What happens when the fractional index has a negative exponent?
  5. How do you apply fractional indices in real-world problems?

Tip: Always simplify the root first before applying the power—it makes calculations easier.

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Math Problem Analysis

Mathematical Concepts

Exponents
Roots
Algebra

Formulas

a^(m/n) = (sqrt[n]{a})^m = (a^m)^(1/n)

Theorems

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Suitable Grade Level

Grades 9-11