Introduction under the sign of the root

In this publication, we will consider how to enter a number (multiplier) or a letter under the sign of a square and higher powers of the root. The information is accompanied by practical examples for better understanding.

Content

The rule for entering under the root sign

Square root

To bring a number (factor) under the square root sign, it should be raised to the second power (in other words, squared), then write the result under the root sign.

Example 1: Let’s put the number 7 under the square root.

Decision:

1. First, let’s square the given number: 72 = 49.

2. Now we just write the calculated number under the root, i.e. we get √49.

Briefly, the introduction under the root sign can be written as follows:

Introduction under the sign of the root

Note: If we are talking about a multiplier, we multiply it by an already existing radical expression.

Example 2: represent the product 3√5 completely under the root of the second degree.

Introduction under the sign of the root

nth root

To bring a number (factor) under the sign of the cubic and higher powers of the root, we raise this number to a given step, then transfer the result to the radical expression.

Example 3: Let’s put the number 6 under the cube root.

Introduction under the sign of the root

Example 4: imagine product 253 under the root of the 5th degree.

Introduction under the sign of the root

Negative number/multiplier

When entering a negative number / multiplier under the root (no matter what degree), the minus sign always remains before the root sign.

Example 5

Introduction under the sign of the root

Entering a letter under the root

To bring a letter under the root sign, we proceed in the same way as with numbers (including negative ones) – we raise this letter to the appropriate degree, and then add it to the root expression.

Example 6

Introduction under the sign of the root

This is true when p > 0, if p is a negative number, then a minus sign must be added before the root sign.

Example 7

Let’s consider a more complicated case: (3 + √8) √5.

Decision:

1. First, we will enter the expression in brackets under the root sign.

Introduction under the sign of the root

2. Now according to we will raise the expression (3 + √8) in a square.

Introduction under the sign of the root

Note: the first and second steps can be interchanged.

3. It remains only to perform the multiplication under the root with the expansion of brackets.

Introduction under the sign of the root

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