/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 48 Evaluate the expression and writ... [FREE SOLUTION] | 91Ó°ÊÓ

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Evaluate the expression and write the result in the form \(a+b i.\) $$\sqrt{\frac{-9}{4}}$$

Short Answer

Expert verified
The result is \(0 + \frac{3}{2}i\).

Step by step solution

01

Understand the Problem

We need to evaluate the expression \( \sqrt{\frac{-9}{4}} \) and express the result in the form \( a + b i \), which is the standard form for complex numbers.
02

Simplify the Square Root

The expression has a negative number under the square root, so we need to factor out \(-1\). Rewriting the expression: \( \sqrt{\frac{-9}{4}} = \sqrt{\frac{-9}{4}} = \sqrt{\frac{-1 \cdot 9}{4}} \).
03

Separate the Components

We know that \( \sqrt{\frac{-1 \cdot 9}{4}} \) can be separated into \( \frac{\sqrt{-1} \cdot \sqrt{9}}{\sqrt{4}} \).
04

Evaluate Each Component

Evaluate each square root separately. We have \( \sqrt{-1} = i \) (where \( i \) is the imaginary unit), \( \sqrt{9} = 3 \), and \( \sqrt{4} = 2 \).
05

Combine the Results

Substitute back into the expression to get \( \frac{i \cdot 3}{2} = \frac{3i}{2} \).
06

Express in Standard Form

The expression \( \frac{3i}{2} \) is already in the form \( a + bi \) where \( a = 0 \) and \( b = \frac{3}{2} \).

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Imaginary Unit
In mathematics, the imaginary unit is a fundamental concept that often puzzles beginners. The imaginary unit is denoted as \( i \) and is defined as the square root of -1. This can be confusing since square roots usually result in a positive or negative real number. However, for negative numbers under the square root, \( i \) provides a new way to define such results.
  • Definition: \( i = \sqrt{-1} \)
  • Key property: \( i^2 = -1 \)
Understanding \( i \) allows mathematicians to work with square roots of negative numbers. For instance, if you see \( \sqrt{-9} \), you can write this as \( \sqrt{9} \times \sqrt{-1} \), which simplifies to \( 3i \). Thus, \( i \) becomes a tool that extends our number system beyond real numbers.
Square Roots
Square roots are a basic mathematical concept that involves finding a number which, when multiplied by itself, gives the original number. It's expressed by the radical symbol \( \sqrt{} \). When dealing with square roots of negative numbers, like in our exercise where we have \( \sqrt{\frac{-9}{4}} \), things get interesting!
  • For positive numbers, the square root gives a real number.
  • For negative numbers, we use the imaginary unit \( i \) and proceed as \( \sqrt{-x} = \sqrt{x} \times i \).
Let’s simplify \( \sqrt{\frac{-9}{4}} \). First, notice \( \frac{-9}{4} = \frac{-1 \times 9}{4} \). We can take the square root of each part separately:- \( \sqrt{-1} = i \)- \( \sqrt{9} = 3 \)- \( \sqrt{4} = 2 \)This gives us \( \frac{3i}{2} \) which represents the square root of \( \frac{-9}{4} \) expressed in terms of an imaginary number.
Expression Simplification
Expression simplification involves reducing an equation or expression to its simplest form. For the expression \( \sqrt{\frac{-9}{4}} \), we aim to express it in the standard complex number form \( a + bi \).
  • Factoring out negative components: Convert negative square roots using \( i \).
  • Breaking down components: Treat each term in the fraction individually, separating numerators and denominators.
  • Combining terms: Take the simplified parts and recombine them following the properties of fractions and complex numbers.
First, express the negative square root as \( \sqrt{\frac{-1 \times 9}{4}} \), separating this into individual terms: \( \frac{\sqrt{-1} \times \sqrt{9}}{\sqrt{4}} \). Evaluate each square root, and you get \( \frac{i \times 3}{2} = \frac{3i}{2} \).
Thus, the solution is \( a = 0 \) and \( b = \frac{3}{2} \), neatly fitting the complex form \( a + bi \). Simplifying expressions brings clarity, ensuring results are in a universally recognized form.

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