How Do You Simplify This Complex Absolute Value Expression?

In summary, absolute value is a mathematical concept that represents the distance of a number from 0 on the number line and is always positive. To simplify absolute value expressions, they can be rewritten as a piecewise function or the rules of absolute value can be used. Simplifying absolute value expressions can make them easier to work with and find solutions to equations. Special cases to consider when simplifying absolute value expressions involve paying attention to the signs of the numbers in expressions with other operations.
  • #1
FlufferNuterFSU
17
0

Homework Statement



I need to simplify the expression below. The absolute value is throwing me off

[tex]
\left[\left|(\alpha + k)^{2}e^{-2i \alpha a} - (\alpha - k)^{2}e^{2i \alpha a}\right|\right]^{2}
[/tex]

Homework Equations



I know [tex]\left|e^{ix}\right| = 1[/tex]

The Attempt at a Solution



I know this eventually simplifies to:
[tex]
(\alpha + k)^{4} + (\alpha - k)^{4} - (\alpha^{2} - k^{2})^{2}(e^{4i \alpha a} + e^{-4i \alpha a})
[/tex]
 
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  • #2
Don't worry about it. I figured it out.
 
  • #3
+ 2(\alpha^{2} + k^{2})(e^{-4i \alpha a} - e^{4i \alpha a})

However, I am having trouble simplifying the expression because of the absolute value. Can you provide any guidance?

To simplify the absolute value in this expression, you can use the property that the absolute value of a product is equal to the product of the absolute values. In this case, you can rewrite the expression as:

\left|(\alpha + k)^{2}e^{-2i \alpha a} - (\alpha - k)^{2}e^{2i \alpha a}\right|^{2} = \left|(\alpha + k)^{2}\right|^{2} \cdot \left|e^{-2i \alpha a}\right|^{2} + \left|(\alpha - k)^{2}\right|^{2} \cdot \left|e^{2i \alpha a}\right|^{2}

Since the absolute value of a complex number is equal to its magnitude, you can simplify the expression further to:

\left|(\alpha + k)^{2}\right|^{2} \cdot 1 + \left|(\alpha - k)^{2}\right|^{2} \cdot 1 = (\alpha + k)^{4} + (\alpha - k)^{4}

This simplification should make it easier to continue with your solution.
 

FAQ: How Do You Simplify This Complex Absolute Value Expression?

What is absolute value?

Absolute value is a mathematical concept that represents the distance of a number from 0 on the number line. It is always positive, regardless of the sign of the number.

How do you simplify absolute value expressions?

To simplify absolute value expressions, you can rewrite them as a piecewise function with one expression for positive values and another expression for negative values. Alternatively, you can use the rules of absolute value, such as the property of absolute value being non-negative, to simplify the expression.

Can you give an example of simplifying an absolute value expression?

Sure, for the expression |5x|, we can simplify it to 5x since the absolute value of any positive number is the number itself. However, for the expression |-5x|, we can simplify it to -5x since the absolute value of any negative number is the opposite of the number.

What is the purpose of simplifying absolute value expressions?

Simplifying absolute value expressions can make them easier to work with in mathematical calculations. It can also help in finding the solutions to equations involving absolute value.

Are there any special cases to consider when simplifying absolute value expressions?

Yes, when simplifying expressions involving absolute value and other operations, such as addition or multiplication, we need to be careful with the signs of the numbers. For example, the expression |x + 2| cannot be simplified to x + 2, but rather to either x + 2 or -(x + 2) depending on the value of x.

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