Chapter 3: Problem 48
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 \( b = \frac{3}{2} \).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
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: \( i^2 = -1 \)
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 \( \sqrt{-x} = \sqrt{x} \times i \).
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 \( a + bi \).
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.
- 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.
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.