Number Systems Flashcards A3204C
1. **Definition of Term: Rational Numbers**
Rational numbers are numbers that can be expressed as the quotient or fraction $\frac{p}{q}$ of two integers, where $p$ and $q$ are integers and $q \neq 0$.
2. **Keywords and Explanations:**
- Quotient: Result of division.
- Integers: Whole numbers including negative, zero, and positive.
- Denominator $q \neq 0$: Division by zero is undefined.
3. **Examples:**
- $\frac{1}{2}$, $-\frac{3}{4}$, $5$ (can be written as $\frac{5}{1}$)
1. **Definition of Term: Irrational Numbers**
Irrational numbers are numbers that cannot be expressed as a simple fraction; their decimal expansions are non-terminating and non-repeating.
2. **Keywords and Explanations:**
- Non-terminating: Decimal goes on forever.
- Non-repeating: No repeating pattern in decimal digits.
3. **Examples:**
- $\sqrt{2}$, $\pi$, $e$
1. **Definition of Term: Real Numbers**
Real numbers include all rational and irrational numbers; they represent all points on the number line.
2. **Keywords and Explanations:**
- Number line: Visual representation of real numbers.
- Includes both rational and irrational numbers.
3. **Examples:**
- $-3$, $0$, $\frac{7}{8}$, $\sqrt{5}$
1. **Definition of Term: Decimal Expansions of Real Numbers**
Decimal expansion is the representation of a real number in decimal form, which can be terminating, non-terminating repeating, or non-terminating non-repeating.
2. **Keywords and Explanations:**
- Terminating decimal: Ends after finite digits.
- Non-terminating repeating decimal: Infinite digits with a repeating pattern.
- Non-terminating non-repeating decimal: Infinite digits without repetition.
3. **Examples:**
- Terminating: $0.75$
- Non-terminating repeating: $0.333...$
- Non-terminating non-repeating: $\pi = 3.14159...$
1. **Definition of Term: Operations on Real Numbers**
Operations include addition, subtraction, multiplication, and division performed on real numbers.
2. **Keywords and Explanations:**
- Closure: Real numbers are closed under these operations.
- Commutative, associative, distributive laws apply.
3. **Examples:**
- $2 + 3 = 5$
- $5 - 7 = -2$
- $4 \times 0.5 = 2$
- $\frac{6}{2} = 3$
1. **Definition of Term: Laws of Exponents for Real Numbers**
Rules that govern the operations involving powers of real numbers.
2. **Keywords and Explanations:**
- Product of powers: $a^m \times a^n = a^{m+n}$
- Quotient of powers: $\frac{a^m}{a^n} = a^{m-n}$
- Power of a power: $(a^m)^n = a^{mn}$
- Power of a product: $(ab)^m = a^m b^m$
- Power of a quotient: $\left(\frac{a}{b}\right)^m = \frac{a^m}{b^m}$
- Zero exponent: $a^0 = 1$ (for $a \neq 0$)
- Negative exponent: $a^{-m} = \frac{1}{a^m}$
3. **Examples:**
- $2^3 \times 2^4 = 2^{3+4} = 2^7 = 128$
- $\frac{5^6}{5^2} = 5^{6-2} = 5^4 = 625$
- $(3^2)^3 = 3^{2 \times 3} = 3^6 = 729$