How to Find Radicals
Finding radicals, or roots of numbers, is an important theme in algebra. The square root of four, for instance, is two, since 2*2 is 4. The cube root of 8 is 2, since 2*2*2 is 8. Finally, the fourth radical of 16 is 2, since 2*2*2*2 is 16. Finding radicals is a matter of determining how you can write the number under the radical sign in terms of perfect squares or perfect cubes, through which the radical can be simplified. Alternatively, you may use a calculator!
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Instructions
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1
Search for perfect cubes or perfect squares in the expression under the radical sign. When finding the cube root of 128, for instance, you could rewrite 128 as 64*2, since 64 is a perfect cube. When finding the square root of 49, notice that 49 is already a perfect square: 7^2 equals 49. Therefore, the answer is simply 7.
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Simplify the radical, using your rewrite. The cube root of 64 is 4, so you can rewrite the radical as 4*cube root(2).
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Input the simplified expression that you wrote, in Step 2, into a calculator. A calculator will give you the decimal version of your answer.
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