Chapter 10: Problem 109
Solve by using the Quadratic Formula. \(2 a^{2}-6 a+3=0\)
Short Answer
Expert verified
The solutions are \(a = \frac{3}{2} + \frac{\sqrt{3}}{2}\) and \(a = \frac{3}{2} - \frac{\sqrt{3}}{2}\).
Step by step solution
01
- Identify the coefficients
Identify the coefficients in the quadratic equation \(2a^2 - 6a + 3 = 0\). Here, the coefficient of \(a^2\) is \(a = 2\), the coefficient of \(a\) is \(b = -6\), and the constant term is \(c = 3\).
02
- Write down the Quadratic Formula
The Quadratic Formula is given by: \[ a = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] Plug in the values of \(a\), \(b\), and \(c\).
03
- Calculate the discriminant
Calculate the discriminant using the formula: \(b^2 - 4ac\). Substituting the given values: \((-6)^2 - 4(2)(3) = 36 - 24 = 12\).
04
- Find the square root of the discriminant
Calculate the square root of the discriminant: \(\sqrt{12} = \sqrt{4 \cdot 3} = 2\sqrt{3}\).
05
- Substitute and simplify
Substitute \(\sqrt{12}\) back into the Quadratic Formula: \[ a = \frac{-(-6) \pm 2\sqrt{3}}{2(2)} \] Simplify: \[ a = \frac{6 \pm 2\sqrt{3}}{4} = \frac{6}{4} \pm \frac{2\sqrt{3}}{4} = \frac{3}{2} \pm \frac{\sqrt{3}}{2} \].
06
- State the solutions
The solutions to the quadratic equation are: \[ a = \frac{3}{2} + \frac{\sqrt{3}}{2} \] and \[ a = \frac{3}{2} - \frac{\sqrt{3}}{2} \].
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Quadratic Equation
A quadratic equation is a type of polynomial equation involving a variable raised to the second power. It generally has the form: ax^2 + bx + c = 0, where a, b, and c are coefficients, and a ≠0. Quadratic equations are essential because they appear in various mathematical contexts, and understanding how to solve them is a key algebraic skill. The quadratic term (ax^2), the linear term (bx), and the constant term (c) together shape the parabola described by the equation when graphed.
Let's solve the example given: 2a^2 - 6a + 3 = 0to see how these principles come together.
Let's solve the example given: 2a^2 - 6a + 3 = 0to see how these principles come together.
Discriminant
The discriminant is a crucial component of the quadratic formula, acting as a determinant of the nature and number of the roots for the equation. It is given by the expression [...theres nothing think better formula here than d = b^2 - 4ac,]
The value of the discriminant can reveal different properties of the roots:
The value of the discriminant can reveal different properties of the roots:
- If the discriminant d > 0, there are two distinct real roots.
- If d = 0, there is one real root (or a repeated root).
- If d < 0, the roots are complex or imaginary.
Roots of Quadratic Equations
The roots (or solutions) of a quadratic equation are the values of the variable that satisfy the equation. These can be found by solving the quadratic formula:
\[a = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\]
In our example, the quadratic formula application yields:
\[a = \frac{-(-6) \pm 2\sqrt{3}}{2(2)}\]
Upon simplification:
\[a = \frac{6 \pm 2\sqrt{3}}{4} = \frac{3}{2} \pm \frac{\sqrt{3}}{2}\]
This unravels two specific roots: .
\[a = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\]
In our example, the quadratic formula application yields:
\[a = \frac{-(-6) \pm 2\sqrt{3}}{2(2)}\]
Upon simplification:
\[a = \frac{6 \pm 2\sqrt{3}}{4} = \frac{3}{2} \pm \frac{\sqrt{3}}{2}\]
This unravels two specific roots: .
Algebraic Solutions
Algebraic solutions refer to solving equations using algebraic manipulations. For quadratic equations, the algebraic solution typically involves using the quadratic formula. Here is the step-by-step algebraic solution for our quadratic equation, 2a^2 - 6a + 3 = 0:
- Identify the coefficients: a = 2, b = -6, c = 3.
- Calculate the discriminant: (b^2 - 4ac) = 12.
- Compute the square root of the discriminant: \[\sqrt{12} = 2\sqrt{3}\]
- Substitute into the quadratic formula: \[a = \frac{6 \pm 2\sqrt{3}}{4}\]
- Simplify to find the roots: \[a = \frac{3}{2} \pm \frac{\sqrt{3}}{2}\] These algebraic steps systematically break down the problem to reach the solution, showing that anyone can master quadratic equations with practice and patience.