1.2 Indices

Indices (or exponents) are used to represent repeated multiplication of a number by itself. Understanding the laws of indices is essential for simplifying algebraic expressions involving powers.

Key Concepts:

Example 1: Applying the Laws of Indices

Simplify: \[ \frac{3^4 \cdot 3^{-2}}{3} \]

Solution:

Step 1: Use the product rule on the numerator: \[ 3^4 \cdot 3^{-2} = 3^{4 + (-2)} = 3^2 \] Step 2: Divide by \(3 = 3^1\): \[ \frac{3^2}{3^1} = 3^{2-1} = 3^1 = 3 \] Therefore, the answer is: \[ 3 \]

Example 2: Zero and Negative Exponents

Simplify: \[ 2^0 + 5^{-2} \]

Solution:

Step 1: Apply the zero exponent rule: \[ 2^0 = 1 \] Step 2: Apply the negative exponent rule: \[ 5^{-2} = \frac{1}{5^2} = \frac{1}{25} \] Step 3: Add the results: \[ 1 + \frac{1}{25} = \frac{26}{25} \]

Example 3: Fractional Exponents

Simplify: \[ 16^{\frac{3}{4}} \]

Solution:

Step 1: Use the fractional exponent rule: \[ 16^{\frac{3}{4}} = \left( \sqrt[4]{16} \right)^3 \] Step 2: Simplify: \[ \sqrt[4]{16} = 2 \quad \Rightarrow \quad 2^3 = 8 \] Therefore, the answer is: \[ 8 \]

Section 1: Number and Numeration Chapters

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