Introduction to Polynomials

Learn polynomial terminology, degree, and classification. Grade 9 Alberta mathematics curriculum.

Lesson 5.1 of Polynomials in Grade 9 Math: Alberta curriculum lessons.

What you'll learn in this lesson

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Types of Polynomials

What Makes Each Polynomial Type Different?Polynomials can have one term or several terms.We name them based on how many terms they have.

Key Point. A term is a number, variable, or the product of both, separated by + or − signs.

1. Monomial (One Term)

A monomial has only one term.. ✅ Examples:3x7y²−4a³9Each example has a single term, no addition or subtraction signs.

2. Binomial (Two Terms)

A binomial has two terms joined by a plus (+) or minus (−) sign.. ✅ Examples:2x + 53y² − 4y−x³ + 2xEach one has exactly two separate parts (terms).

3. Trinomial (Three Terms)

A trinomial has three terms.. ✅ Examples:x² + 3x + 24y³ − y + 1−2x² + 5x − 3Each term may have different exponents or coefficients, but they are all joined by + or −.

4. Polynomial (Four or More Terms)

If an expression has four or more terms, we usually just call it a polynomial.. ✅ Examples:x³ + 2x² − 4x + 63y⁴ − 5y² + y − 7There's no special name beyond "polynomial". We simply describe it by the number of terms.

Tip to Remember

💡 Quick Counting Method. You can quickly count the number of terms by counting how many + or − signs appear (each separates terms).

For example:. 4x³ + 3x² − x + 5has 4 terms, so it's a polynomial.

Equivalent Polynomials

A binomial is a polynomial with two terms.. For example:2x + 5If we write it as5 + 2xit still means the same thing. Both expressions are equivalent.

Key Point. The order of the terms doesn't matter as long as the coefficients, variables, and exponents are the same.

This same idea applies to any polynomial with more terms.

Worked example: Identifying a Polynomial

4x² + 2x + 7This is a polynomial because: It has three terms separated by + signs.; The exponents (2 and 1) are whole numbers.; There are no fractions or roots involving variables.

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