Questions tagged [radicals]

For questions involving radical of numbers or radical of expressions (i.e. numbers/expressions raised to the power of a fraction).

A radical expression is any mathematical expression containing a radical symbol $~(√~)~$.

Many people mistakenly call this a 'square root' symbol, and many times it is used to determine the square root of a number. However, it can also be used to describe a cube root, a fourth root, or higher.

When the radical symbol is used to denote any root other than a square root, there will be a superscript number in the $'V'$-shaped part of the symbol. For example, $~3\sqrt{8}~$ means to find the cube root of $~8~$. If there is no superscript number, the radical expression is calling for the square root.

The term underneath the radical symbol is called the radicand.

Steps required for Simplifying Radicals:

Step $~1~$: Find the prime factorization of the number inside the radical. Start by dividing the number by the first prime number $~2~$ and continue dividing by $~2~$ until you get a decimal or remainder. Then divide by $~3,~ 5,~ 7,~$ etc. until the only numbers left are prime numbers. Click on the link to see some examples of Prime Factorization. Also factor any variables inside the radical.

Step $~2~$: Determine the index of the radical. The index tells you how many of a kind you need to put together to be able to move that number or variable from inside the radical to outside the radical. For example, if the index is $~2~$ (a square root), then you need two of a kind to move from inside the radical to outside the radical. If the index is $~3~$ (a cube root), then you need three of a kind to move from inside the radical to outside the radical.

Step $~3~$: Move each group of numbers or variables from inside the radical to outside the radical. If there are nor enough numbers or variables to make a group of two, three, or whatever is needed, then leave those numbers or variables inside the radical. Notice that each group of numbers or variables gets written once when they move outside the radical because they are now one group.

Step $~4~$: Simplify the expressions both inside and outside the radical by multiplying. Multiply all numbers and variables inside the radical together. Multiply all numbers and variables outside the radical together.

A closely related tag is the tag.

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How can $\sqrt{4+2\sqrt{3}} = 1+\sqrt{3}$?

I'm a high school student and I'm currently studying a lot of Numerical Sets and Radicals then I came across with a problem that wants me to explain why $\sqrt{4+2\sqrt{3}} = 1+\sqrt{3}$, but I don't know how to do, this was my equation: $\sqrt{4} +…
iszwnc
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simplify rational expression with roots

$\frac{\sqrt[3]{25}+\sqrt[3]{5x}+\sqrt[3]{x^2} }{\sqrt[3]{x}-\sqrt[3]{5}}$ How do i simplify this and how do I get a non-square value at the bottom? difference of cubes tells me that $a^3-b^3=(a-b)(a^2+2ab+b^2)$ and if put $\sqrt[3]{x}=a$ and…
Fanny
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Procedure about simplifying radicals

I have this: $$\frac {(2n+1)^3-8n(n^2-1)}{\sqrt{n(n+1)(n+2)(n+3)}}=\sqrt{\frac{144n^4+336n^3+220n^2+28n+1}{n(n+1)(n+2)(n+3)}}$$ What does this mean? What's the step by step procedure to do this? Thanks :)
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Square Root of $9a + 36\sqrt{3ax} + 108x$

An old mathematics book found on Google asserts that: Square root of $9a + 36\sqrt{3ax} + 108x$ Equals to $3\sqrt{a} + 6\sqrt{3x}$ I find this incorrect, but am not 100% sure. My derivation is: Let $m = \sqrt{a}$ and $n = 2\sqrt{3x}$, then…
jimfan
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Please give me the method of writing $\sqrt{33 + 12 \sqrt 6}$ in the form $a + b \sqrt c$

I have the answer but I need the method. My professor wants it in : a + b √c. He said a hint would be to use algebra.
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$\sqrt{x + \sqrt {x + \sqrt{ x + \cdots } } } = 5$ then find the value of $x$.

I am trying to solve this problem but nothing is thought on my mind. Please any one help me to solve this problem $\sqrt{x + \sqrt {x + \sqrt{ x + \cdots } } } = 5$ then find the value of $x$.
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Simplifying an expression with a nested radical

I'm doing some work on functions and have come across a problem in which I need to simplify a certain expression. I can't move any further on because I'm unsure of how to simplify this expression! Here it…
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-0.73th root not working?

I have a math assignment due tomorrow morning, nearly done however I've stumbleded upon a problem of mine. I'm normally using Wolfram Alpha for my calculations, which has worked for everything so far - besides this. My problem is:…
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