Mathematics
Grade 11
15 min
Roots of integers
Roots of integers
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Define and identify the index, radicand, and principal root of a radical expression.
Evaluate the nth root of any integer, including perfect squares, cubes, and higher powers.
Simplify radical expressions by finding the largest perfect nth power factor of the radicand.
Distinguish between real and imaginary roots for even and odd indices.
Calculate the roots of negative integers, expressing answers using the imaginary unit 'i' when necessary.
Apply the product and quotient rules to simplify expressions involving roots of integers.
If a cube has a volume of 216 cubic centimeters, how can you find the length of one of its sides? 🧊 That's where cube roots come in!
This tutorial explores the concept of finding the 'nth root' of an i...
2
Key Concepts & Vocabulary
TermDefinitionExample
Radical ExpressionAn expression containing a radical symbol (√). It consists of an index, a radicand, and the radical symbol itself.In the expression `∛27`, the entire expression is the radical. `3` is the index, and `27` is the radicand.
IndexThe small number written to the left of the radical symbol that indicates which root is to be taken.In `⁵√32`, the index is 5. If no index is written, it is assumed to be 2 (a square root).
RadicandThe number or expression inside the radical symbol.In `√81`, the radicand is 81. In `∛-64`, the radicand is -64.
Principal RootThe unique, non-negative real root of a non-negative real number. For even indices, the radical symbol denotes only the principal root.The principal square root of 25, written as `√25`, is 5. Although (-5)² =...
3
Core Formulas
Definition of nth Root
`ⁿ√a = b` if and only if `bⁿ = a`
This is the fundamental definition connecting radicals and exponents. The nth root of 'a' is the number 'b' that, when raised to the nth power, equals 'a'.
Product Rule for Radicals
`ⁿ√ab = ⁿ√a * ⁿ√b`
Use this rule to split a radical of a product into a product of radicals. This is key for simplifying radicals by factoring out perfect nth powers. (Note: `a` and `b` must be non-negative if `n` is even).
Quotient Rule for Radicals
`ⁿ√(a/b) = (ⁿ√a) / (ⁿ√b)`
Use this rule to split a radical of a quotient into a quotient of radicals. (Note: `a` must be non-negative if `n` is even, and `b` must be positive if `n` is even).
Roots of Negative Numbers
If `n` is odd, `ⁿ√-a = -ⁿ√a`. If...
5 more steps in this tutorial
Sign up free to access the complete tutorial with worked examples and practice.
Sign Up Free to ContinueSample Practice Questions
Challenging
Simplify the expression `√-12 * √-3`.
A.-6
B.6
C.6i
D.-6i
Challenging
Simplify the expression `∜(1250/2)`.
A.25
B.5√5
C.5
D.5∜2
Challenging
The simplified form of an expression `∛x` is `-4∛2`. What is the integer value of `x`?
A.-64
B.-128
C.-32
D.-256
Want to practice and check your answers?
Sign up to access all questions with instant feedback, explanations, and progress tracking.
Start Practicing Free