Practice Roots as Inverse Growth in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Roots reverse the process of exponentiation: the nnth root of aa finds the number that, raised to the nnth power, produces aa. For example, 83=2\sqrt[3]{8} = 2 because 23=82^3 = 8.

If 32=93^2 = 9, then 9=3\sqrt{9} = 3. The root asks: 'What number squared gives 9?'

Showing a random 20 of 50 problems.

Example 1

easy
Find 100\sqrt{100}.

Example 2

easy
Find 144\sqrt{144} and 273\sqrt[3]{27}.

Example 3

challenge
For which real numbers aa does a2=a\sqrt{a^2} = a hold, and where does it fail? Justify.

Example 4

medium
Estimate 30\sqrt{30} to one decimal place by bracketing it between perfect squares.

Example 5

easy
True or false: 36=โˆ’6\sqrt{36} = -6.

Example 6

medium
Solve x=9\sqrt{x} = 9 for xx, and verify your answer.

Example 7

medium
A square has area AA and you find its side is 99. What was AA, and what operation recovers the side from AA?

Example 8

easy
Is 16\sqrt{16} equal to 163\sqrt[3]{16}?

Example 9

easy
Find โˆ’83\sqrt[3]{-8}.

Example 10

easy
Find 273\sqrt[3]{27}.

Example 11

medium
Simplify 36+83\sqrt{36} + \sqrt[3]{8}.

Example 12

medium
Between which two consecutive integers does 75\sqrt{75} lie? Estimate to one decimal.

Example 13

hard
Simplify 12โ‹…27\sqrt{12} \cdot \sqrt{27}.

Example 14

hard
Rationalize and simplify 63\dfrac{6}{\sqrt{3}}.

Example 15

easy
Find 1253\sqrt[3]{125}.

Example 16

medium
Solve x3=64x^3 = 64 for real xx.

Example 17

medium
A square's area grows from 2525 to 100100. By what factor does its side grow?

Example 18

medium
Solve x2=49x^2 = 49 for all real xx.

Example 19

easy
Since 82=648^2 = 64, what is 64\sqrt{64}? Explain roots as inverses of powers.

Example 20

medium
Which is larger: 40\sqrt{40} or 2102\sqrt{10}?