Like Radicals: Find Radicals Similar To ∛(7x)

by Kenji Nakamura 46 views

Hey guys! Ever stumbled upon a math problem that looks like it's speaking a different language? Well, today, we're going to tackle one of those tricky topics in mathematics: like radicals. Specifically, we're diving deep into understanding what like radicals are and how to identify them. We'll break down the question: "Which of the following is a like radical to 7x3\sqrt[3]{7x}?" and explore the answer options. So, buckle up, and let's make radicals less radical!

Understanding Radicals: The Basics

Before we jump into like radicals, let's quickly refresh our understanding of radicals in general. A radical is a mathematical expression that involves a root, such as a square root, cube root, or any nth root. The general form of a radical is an\sqrt[n]{a}, where:

  • n is the index (the small number indicating the type of root).
  • The radical symbol \sqrt{} is the radical sign.
  • a is the radicand (the expression under the radical sign).

For example, in 83\sqrt[3]{8}, the index is 3, the radical sign is 3\sqrt[3]{}, and the radicand is 8. This expression represents the cube root of 8, which is 2 because 23=82^3 = 8.

Delving Deeper into Radicands

The radicand is arguably the most important part when it comes to identifying like radicals. It's the expression tucked away inside the radical symbol, and it can be a number, a variable, or even a combination of both. Think of it as the 'stuff' we're trying to take the root of. For example, in the radical expression 5x\sqrt{5x}, the radicand is 5x5x. Understanding the radicand is crucial because like radicals share a common radicand. This means that not just the numerical part, but also the variable part under the radical must be identical for radicals to be considered 'like'. This becomes particularly important when simplifying radicals or performing operations like addition and subtraction, as we can only combine like radicals. The radicand, therefore, dictates which radicals can 'play together' in the world of mathematical operations.

The Role of the Index in Radical Expressions

The index of a radical is a small number nestled in the crook of the radical symbol, and it indicates what 'root' we're taking. This little number is super important because it tells us how many times a number must be multiplied by itself to get the radicand. For instance, if the index is 2, we're looking for a square root – a number that, when multiplied by itself, equals the radicand. If the index is 3, it's a cube root – we need a number multiplied by itself three times. Now, here's the key: for radicals to be considered 'like,' they must have the same index. So, you can't simply compare \sqrt{ } (which implies an index of 2) with 3\sqrt[3]{ } just because they have a similar radicand. The index sets the stage for what kind of root we're seeking, and it's a non-negotiable factor when identifying like radicals. Remembering this will save you from many common mistakes in simplifying and combining radical expressions.

What are Like Radicals?

Now that we've got the basics down, let's define what like radicals actually are. Like radicals, also known as similar radicals, are radicals that have the same index and the same radicand. This means that both the type of root (square root, cube root, etc.) and the expression under the radical sign must be identical for two radicals to be considered