Mathematics
Grade 9
15 min
Identify numbers as even or odd
Identify numbers as even or odd
Tutorial Preview
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Introduction & Learning Objectives
Learning Objectives
Define even and odd numbers using the algebraic forms 2k and 2k+1.
Determine the parity (evenness or oddness) of the result of arithmetic operations on integers.
Evaluate the parity of a polynomial expression for an integer input without direct calculation.
Algebraically identify a function as even by testing if f(-x) = f(x).
Algebraically identify a function as odd by testing if f(-x) = -f(x).
Distinguish between even, odd, and functions that are neither.
Connect the algebraic properties of even and odd functions to the symmetry of their graphs.
Ever notice how the graph of y = x² is perfectly symmetrical across the y-axis, but y = x³ is not? 🤔 This symmetry is directly related to the concepts of 'even' and 'odd' applied to functio...
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Key Concepts & Vocabulary
TermDefinitionExample
ParityThe property of an integer of being either even or odd. It is a fundamental concept in number theory.The number 17 has a parity of 'odd'. The number -4 has a parity of 'even'.
Even Number (Algebraic Form)An integer 'n' that can be expressed in the form n = 2k, where 'k' is any integer.The number 12 is even because it can be written as 2 * 6.
Odd Number (Algebraic Form)An integer 'n' that can be expressed in the form n = 2k + 1, where 'k' is any integer.The number -9 is odd because it can be written as 2 * (-5) + 1.
Even FunctionA function f(x) for which f(-x) = f(x) for all x in its domain. The graph of an even function is symmetric with respect to the y-axis.f(x) = x² is an even function because f(-x)...
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Core Formulas
Rules of Parity for Operations
Let E be an even integer and O be an odd integer. Then: E ± E = E, O ± O = E, E ± O = O. Also: E * (any integer) = E, O * O = O.
Use these rules to quickly determine the parity of a complex arithmetic expression without calculating the final value. This is especially useful in algebra.
Rule of Parity for Integer Powers
Let O be an odd integer and E be an even integer. For any positive integer n: O^n = O, E^n = E.
This rule simplifies determining the parity of terms with exponents. An odd number multiplied by itself any number of times will always be odd.
The Function Parity Test
Given a function f(x): 1. Calculate f(-x). 2. If f(-x) = f(x), the function is EVEN. 3. If f(-x) = -f(x), the function is ODD. 4. If neither is true, the function...
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Sign Up Free to ContinueSample Practice Questions
Easy
Which algebraic expression correctly defines any even integer 'n', where 'k' is also an integer?
A.n = k + 2
B.n = 2k
C.n = 2k + 1
D.n = k - 1
Easy
A function f(x) is defined as an odd function if it satisfies which of the following conditions for all x in its domain?
A.f(-x) = f(x)
B.f(-x) = -f(x)
C.f(x) = f(1/x)
D.f(-x) = f(x) + 1
Easy
Let O be an odd integer. What is the parity of the result of O + O?
A.Odd
B.Even
C.Neither even nor odd
D.Depends on the value of O
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