Chapter 7: Problem 37
Without solving the given equations, determine the character of the roots. $$3.6 t^{2}+2.1=7.7 t$$
Short Answer
Expert verified
The equation has two distinct real roots.
Step by step solution
01
Write the equation in standard form
The given equation is \(3.6t^2 + 2.1 = 7.7t\). Begin by rewriting this equation in the standard quadratic form \(at^2 + bt + c = 0\). Subtract \(7.7t\) from both sides to achieve this: \[3.6t^2 - 7.7t + 2.1 = 0\]
02
Identify coefficients
In the standard form of the quadratic equation \(at^2 + bt + c = 0\), identify the coefficients: \(a = 3.6\), \(b = -7.7\), and \(c = 2.1\).
03
Calculate the discriminant
The character of the roots of a quadratic equation is determined by its discriminant, \(\Delta = b^2 - 4ac\). Substitute the values of the coefficients: \[\Delta = (-7.7)^2 - 4 \times 3.6 \times 2.1\] Calculate the values: \[\Delta = 59.29 - 30.24\] \[\Delta = 29.05\]
04
Determine the nature of the roots
The discriminant \(\Delta\) determines the nature of the roots: - If \(\Delta > 0\), the quadratic equation has two distinct real roots.- If \(\Delta = 0\), the quadratic equation has exactly one real root (a repeated root).- If \(\Delta < 0\), the quadratic equation has two complex conjugate roots.Since \(\Delta = 29.05 > 0\), the quadratic equation has two distinct real roots.
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.
Discriminant
The discriminant is a fundamental concept in determining the characteristics of the roots of a quadratic equation. When you have a quadratic equation in standard form, which is expressed as \( ax^2 + bx + c = 0 \), the discriminant \( \Delta \) is calculated using the formula:
- \( \Delta = b^2 - 4ac \)
- If \( \Delta > 0 \), the equation has two distinct real roots.
- If \( \Delta = 0 \), there is exactly one real root, known as a double or repeated root.
- If \( \Delta < 0 \), the equation has two complex roots, which are not real numbers.
Real Roots
Real roots are the solutions to a quadratic equation that lie within the set of real numbers. In simpler terms, they're the x-values at which the graph of the quadratic equation touches or crosses the x-axis. These are important in many mathematical contexts because they are the solutions that you can "see" or have practical interpretations in real-world problems. When analyzing the roots of a quadratic equation, knowing the value of the discriminant is essential because:
- When \( \Delta > 0 \), there are two distinct points of intersection with the x-axis, giving us two unique real roots.
- If \( \Delta = 0 \), the parabola touches the x-axis at only one point, resulting in a single real root that is repeated.
- If \( \Delta < 0 \), the graph does not intersect the x-axis, and there are no real roots, only complex ones.
Standard Form
The standard form of a quadratic equation is instrumental because it organizes the equation in a way that easily reveals its coefficients, crucial for further analysis. The standard form of a quadratic equation is expressed as:
- \( ax^2 + bx + c = 0 \)
- \( a \) is the coefficient of the squared term, \( x^2 \).
- \( b \) is the coefficient of the linear term, \( x \).
- \( c \) is the constant term, independent of \( x \).