Finding Complex Solutions Of 13x² + 5x + 1 = 0 A Step-by-Step Guide

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Introduction

In this comprehensive article, we delve into the fascinating realm of complex numbers to solve the quadratic equation 13x² + 5x + 1 = 0. Quadratic equations, fundamental in algebra, often yield solutions that extend beyond the set of real numbers. These solutions, known as complex solutions, involve the imaginary unit i, where i² = -1. This exploration will not only provide the solutions to the given equation but also illuminate the underlying principles and methodologies for tackling such problems. We will embark on a journey through the quadratic formula, discriminant analysis, and the nature of complex roots, ensuring a thorough understanding of the subject matter. Whether you are a student grappling with quadratic equations or a mathematics enthusiast seeking to expand your knowledge, this article will serve as a valuable resource. Our focus will be on delivering clear, concise explanations, coupled with step-by-step solutions, to make the learning process both engaging and effective. Let's embark on this mathematical journey to unravel the complex solutions of the equation at hand.

Understanding Quadratic Equations and the Quadratic Formula

Before diving into the specifics of the equation 13x² + 5x + 1 = 0, it is crucial to establish a firm understanding of quadratic equations in general. A quadratic equation is a polynomial equation of the second degree, which can be expressed in the standard form ax² + bx + c = 0, where a, b, and c are constants, and a is not equal to zero. The solutions to a quadratic equation, also known as roots or zeros, represent the values of x that satisfy the equation. These roots can be real or complex, depending on the coefficients a, b, and c.

The quadratic formula is the cornerstone for solving quadratic equations. This formula provides a direct method for finding the roots of any quadratic equation, regardless of whether the roots are real or complex. The formula is given by:

x = (-b ± √(b² - 4ac)) / (2a)

In this formula, the expression b² - 4ac plays a pivotal role and is known as the discriminant. The discriminant provides valuable information about the nature of the roots. If the discriminant is positive, the equation has two distinct real roots. If it is zero, the equation has exactly one real root (a repeated root). However, if the discriminant is negative, the equation has two complex conjugate roots. Complex roots arise when the square root of a negative number is encountered, leading to the involvement of the imaginary unit i.

The quadratic formula is derived by completing the square, a technique that transforms the quadratic equation into a perfect square trinomial. This method not only yields the formula but also provides insight into the underlying structure of quadratic equations. Understanding the derivation of the quadratic formula enhances one's appreciation for its power and applicability.

Applying the Quadratic Formula to 13x² + 5x + 1 = 0

Now, let's apply our knowledge of quadratic equations and the quadratic formula to the specific equation 13x² + 5x + 1 = 0. First, we identify the coefficients a, b, and c. In this case, a = 13, b = 5, and c = 1. These coefficients will be plugged into the quadratic formula to determine the solutions for x.

Substituting these values into the quadratic formula, we get:

x = (-5 ± √(5² - 4 * 13 * 1)) / (2 * 13)

Simplifying the expression under the square root, we have:

x = (-5 ± √(25 - 52)) / 26

x = (-5 ± √(-27)) / 26

Notice that we have a negative number under the square root, indicating that the solutions will be complex. The square root of -27 can be expressed in terms of the imaginary unit i as follows:

√(-27) = √(27 * -1) = √(27) * √(-1) = 3√3 * i

Thus, the solutions for x become:

x = (-5 ± 3√3 * i) / 26

These are the two complex solutions to the quadratic equation 13x² + 5x + 1 = 0. They are complex conjugates, meaning they have the same real part but opposite imaginary parts. This is a common characteristic of complex roots of quadratic equations with real coefficients. The solutions can be written separately as:

x₁ = (-5 + 3√3 * i) / 26

x₂ = (-5 - 3√3 * i) / 26

Analyzing the Discriminant and the Nature of Roots

The discriminant, as mentioned earlier, plays a crucial role in determining the nature of the roots of a quadratic equation. In our case, the discriminant is b² - 4ac = 5² - 4 * 13 * 1 = 25 - 52 = -27. Since the discriminant is negative, we can definitively say that the equation has two complex conjugate roots. This aligns perfectly with the solutions we obtained using the quadratic formula.

If the discriminant were positive, the equation would have two distinct real roots. For instance, if the discriminant were 9, the square root would be 3, leading to two different real solutions. If the discriminant were zero, the equation would have exactly one real root, which is often referred to as a repeated root. This occurs when the expression under the square root vanishes, resulting in a single solution.

Understanding the relationship between the discriminant and the nature of roots is essential for quickly assessing the type of solutions a quadratic equation will have. This knowledge can save time and effort in problem-solving, as it allows one to anticipate the form of the solutions before applying the quadratic formula.

Expressing Complex Solutions in Standard Form

Complex numbers are typically expressed in the standard form a + bi, where a is the real part and b is the imaginary part. Our solutions, x₁ = (-5 + 3√3 * i) / 26 and x₂ = (-5 - 3√3 * i) / 26, can be rewritten in this standard form by separating the real and imaginary parts:

x₁ = -5/26 + (3√3 / 26)i

x₂ = -5/26 - (3√3 / 26)i

This representation clearly shows the real part, which is -5/26, and the imaginary parts, which are (3√3 / 26) and -(3√3 / 26) for x₁ and x₂, respectively. Expressing complex solutions in standard form facilitates comparisons and further operations involving complex numbers.

The standard form also highlights the complex conjugate relationship between the two solutions. The real parts are identical, while the imaginary parts differ only in sign. This characteristic is a direct consequence of the quadratic formula and the properties of complex numbers. The symmetry in the solutions reflects the fundamental nature of quadratic equations with real coefficients and negative discriminants.

Verification and Significance of Complex Solutions

To ensure the correctness of our solutions, we can substitute them back into the original equation, 13x² + 5x + 1 = 0. This process will demonstrate that the solutions indeed satisfy the equation. Let's substitute x₁ = -5/26 + (3√3 / 26)i into the equation:

13(-5/26 + (3√3 / 26)i)² + 5(-5/26 + (3√3 / 26)i) + 1

Expanding and simplifying this expression, we should arrive at 0, confirming that x₁ is a valid solution. A similar process can be applied to x₂.

The existence of complex solutions expands the scope of quadratic equations and their applications. While real solutions correspond to points where the parabola intersects the x-axis, complex solutions indicate that the parabola does not intersect the x-axis. These complex solutions are not merely abstract mathematical concepts; they have practical applications in various fields, including electrical engineering, quantum mechanics, and signal processing.

In electrical engineering, complex numbers are used to represent alternating current (AC) circuits, where impedance, a measure of opposition to current flow, is a complex quantity. In quantum mechanics, complex wave functions describe the probability amplitudes of particles. In signal processing, complex Fourier transforms are used to analyze and manipulate signals. These applications underscore the importance of understanding and working with complex numbers.

Conclusion

In this article, we have successfully navigated the complexities of solving the quadratic equation 13x² + 5x + 1 = 0. We began by establishing the fundamental principles of quadratic equations and the quadratic formula. We then applied the formula to the specific equation, encountered a negative discriminant, and unearthed the complex solutions.

The solutions, x₁ = -5/26 + (3√3 / 26)i and x₂ = -5/26 - (3√3 / 26)i, exemplify the nature of complex conjugate roots. We analyzed the discriminant, confirming its role in determining the nature of roots. We also expressed the solutions in standard form, facilitating clarity and comparison.

Furthermore, we discussed the significance of complex solutions in various fields, highlighting their practical applications beyond theoretical mathematics. The journey through this problem has not only provided the solutions but also deepened our understanding of quadratic equations and complex numbers. The skills and knowledge acquired here will undoubtedly be valuable in tackling more complex mathematical challenges in the future. The world of mathematics is vast and intricate, and each problem solved is a step further in our understanding of its beauty and power.