Mathematics
Grade 11
15 min
Find roots using a calculator
Find roots using a calculator
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Find the square root and cube root of any positive number using dedicated calculator keys.
Calculate any nth root (e.g., 4th root, 5th root) using the generic root function (ⁿ√x or x√y) on a scientific calculator.
Convert a radical expression into its equivalent rational exponent form to find its value.
Accurately input expressions with rational exponents into a calculator, using parentheses correctly.
Evaluate complex expressions involving multiple roots and arithmetic operations.
Approximate the value of roots of non-perfect numbers and round the answer to a specified number of decimal places.
Ever wondered how financial analysts calculate the average annual return on an investment over 10 years? 📈 They use higher-order roots, and a calculator is their...
2
Key Concepts & Vocabulary
TermDefinitionExample
RadicalAn expression that uses a root symbol (√). It consists of an index, a radicand, and the radical symbol.In the expression ∛(64), the entire term is the radical.
IndexThe small number outside the radical symbol that indicates which root to take. If no index is written, it is assumed to be 2 (a square root).In ⁴√(81), the index is 4.
RadicandThe number or expression inside the radical symbol.In ⁷√(128), the radicand is 128.
nth RootA number that, when multiplied by itself 'n' times, equals the radicand. For example, the nth root of 'x' is a number 'y' such that yⁿ = x.The 5th root of 32 is 2, because 2⁵ = 32.
Rational ExponentAn exponent expressed as a fraction, which provides an alternative way to write a radical expression.The radi...
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Core Formulas
The nth Root Function
y = \sqrt[n]{x}
This represents finding the nth root of x. On most calculators, this is done using a key labeled ⁿ√x, x√y, or √[x]. You typically enter the index (n), press the function key, and then enter the radicand (x).
The Rational Exponent Rule
\sqrt[n]{x} = x^{1/n}
This is the most powerful and universal way to find a root. Any radical can be rewritten as the radicand raised to the power of 1 divided by the index. This form is easy to enter into any scientific calculator.
The Power over Root Rule
\sqrt[n]{x^m} = (\sqrt[n]{x})^m = x^{m/n}
This rule extends the rational exponent concept to cases where the radicand is raised to a power. It's useful for simplifying and evaluating more complex radical expressions.
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Sign Up Free to ContinueSample Practice Questions
Easy
Using a calculator, what is the value of √361?
A.18
B.19
C.21
D.180.5
Easy
Using a calculator, find the value of ∛1728.
A.11
B.14
C.12
D.13
Easy
Which expression is equivalent to ⁷√x and can be used for calculation on a scientific calculator?
A.x^(1/7)
B.7x
C.x⁷
D.x/7
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