How to simplify surds
If you have ever encountered a surd in mathematics, you may have found yourself feeling overwhelmed. Surds can appear complicated and intimidating at first glance. However, with the right techniques and a little practice, you can simplify surds and make them much more manageable.
So, what exactly is a surd? A surd is a square root of a non-square number. In other words, it is an irrational number expressed in the form √n, where n is a positive integer that is not a perfect square.
Simplifying surds involves finding the simplest form of the square root, removing any unnecessary factors, and simplifying any fractions or decimals that may be present. By simplifying surds, you can make calculations easier and gain a deeper understanding of the underlying mathematical concepts.
Basic rules for simplifying surds
Simplifying surds can seem daunting at first, but by following a few basic rules, you can make the process much simpler. Here are some rules to remember:
Rule 1: Prime factors
Find the prime factors of the number under the square root sign. Prime numbers are numbers that have only two factors: 1 and itself.
Rule 2: Pair up the factors
Pair up the factors in groups of two. For example, if the number under the square root sign is 50, you would pair up the factors 2 and 25.
Rule 3: Use the rules of square roots
Remember that the square root of a product is equal to the square root of each factor multiplied together. For example, √(2 * 25) is equal to √2 * √25.
Rule 4: Simplify the surd
Continue simplifying the square roots of the factors. For example, √2 * √25 can be simplified as √2 * 5, which is equal to √10.
By following these basic rules, you can simplify surds and make complex calculations much easier to handle.
Simplifying surds with addition and subtraction
When you are dealing with surds, it is important to know how to simplify them. We can simplify surds by adding or subtracting them.
To add or subtract surds, we need to make sure that we have the same radicand, which is the number inside the square root symbol. If the radicand is different, we need to simplify them first.
Let’s take an example:
We have two surds: √12 and √18. Our goal is to simplify them by adding or subtracting.
To simplify these surds, we need to find their simplified form first. We can simplify the radicands by breaking them down into their prime factors.
Let’s find the prime factors of 12: 12 = 2 × 2 × 3 = √(2 × 2 × 3) = √(2^2 × 3)
Similarly, let’s find the prime factors of 18: 18 = 2 × 3 × 3 = √(2 × 3 × 3) = √(2 × 3^2)
Now we have: √12 = √(2^2 × 3) and √18 = √(2 × 3^2)
We can simplify these surds further by taking out the common factors outside the square roots:
√12 = 2√3
√18 = 3√2
Now that we have simplified forms of both surds, we can add or subtract them. Remember, we need to have the same radicand.
Let’s add √12 and √18:
2√3 + 3√2 = (√(2^2 × 3)) + (√(2 × 3^2)) = 2√3 + 3√2
We cannot simplify this further, so our final answer is 2√3 + 3√2.
In the case of subtraction, we just need to change the operation from addition to subtraction.
For example: subtracting √18 from √12, we have 2√3 – 3√2.
Remember, always simplify the surds before adding or subtracting them.
Simplifying surds with multiplication and division
When it comes to simplifying surds, multiplication and division can be useful operations. These operations allow us to simplify complex surds into more manageable forms.
Multiplication of two surds is relatively straightforward. To multiply two surds together, simply multiply their coefficients (numbers outside the square roots) and then multiply the contents of the surds (numbers inside the square roots).
For example, to multiply √3 and √2, you would do the following:
√3 * √2 = √(3 * 2) = √6
Division of surds can also be simplified using a similar process. To divide one surd by another, divide their coefficients and then divide the contents of the surds.
For example, to divide √6 by √2, you would do the following:
√6 / √2 = √(6/2) = √3
It’s worth noting that when you multiply or divide surds, there are instances where the resulting surd can be further simplified.
By applying these simple rules of multiplication and division, you can simplify surds and make them easier to work with in various mathematical operations.
Examples of simplifying surds
Here are some examples demonstrating how to simplify surds:
Example 1:
√12
We can simplify this surd by breaking down 12 into its prime factors: 2 x 2 x 3.
√12 = √(2 x 2 x 3)
Next, we take out the pairs of the same numbers from under the square root:
√(2 x 2 x 3) = √(2 x 2) x √3
Now, we can simplify the square root of the pair of 2’s:
√(2 x 2) = 2
So, our simplified form is:
√12 = 2√3
Example 2:
√27
We can also simplify this surd by finding the perfect square factors of 27, which is 9.
√27 = √(9 x 3)
Now, we can simplify the square root of 9:
√(9 x 3) = 3√3
So, the simplified form of √27 is 3√3.
Example 3:
√72
We can simplify this surd by breaking down 72 into its prime factors: 2 x 2 x 2 x 3 x 3.
√72 = √(2 x 2 x 2 x 3 x 3)
Next, we take out the pairs of the same numbers from under the square root:
√(2 x 2 x 2 x 3 x 3) = √(2 x 2 x 3 x 3) x √2
Now, we can simplify the square root of the pair of 2’s and the pair of 3’s:
√(2 x 2 x 3 x 3) = 2 x 3 = 6
So, our simplified form is:
√72 = 6√2