Chapter 6: Problem 50
\(-x^{2}+6 x+16=0\)
Short Answer
Expert verified
The solutions are \(x = -2\) and \(x = 8\).
Step by step solution
01
Identify the coefficients
First, identify the coefficients from the quadratic equation. The equation is \(-x^{2}+6x+16=0\). We rewrite it as \(-1x^{2}+6x+16=0\). The coefficients are \(a = -1\), \(b = 6\), and \(c = 16\).
02
Apply the quadratic formula
The quadratic formula is \(x=\frac{-b \pm \sqrt{b^{2}-4ac}}{2a}\). Substitute the values \(a = -1\), \(b = 6\), and \(c = 16\) into the formula.
03
Calculate the discriminant
Calculate the discriminant using \(b^{2}-4ac\): \[b^{2} - 4ac = 6^{2} - 4(-1)(16) = 36 + 64 = 100\]
04
Solve for x using the quadratic formula
Substitute the values into the quadratic formula to solve for \(x\):\[x = \frac{-6 \pm \sqrt{100}}{-2}\]. Simplifying, we find \(\sqrt{100} = 10\), so the equation becomes \[x = \frac{-6 \pm 10}{-2}\].
05
Calculate the solutions
We have two solutions: 1) \(x = \frac{-6 + 10}{-2} = \frac{4}{-2} = -2\)2) \(x = \frac{-6 - 10}{-2} = \frac{-16}{-2} = 8\).
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.
Quadratic Formula
The quadratic formula is a universal method used to find the solutions, or roots, of a quadratic equation. A quadratic equation is generally expressed in the form \(ax^2 + bx + c = 0\), where \(a\), \(b\), and \(c\) are constants with \(a eq 0\). The quadratic formula is:
- \(x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\)
Discriminant
The discriminant in a quadratic equation helps in determining the nature of the roots. It is the expression under the square root in the quadratic formula: \(b^2 - 4ac\). The value of the discriminant points to the type of solutions:
- If \(b^2 - 4ac > 0\), there are two distinct real solutions.
- If \(b^2 - 4ac = 0\), there is exactly one real solution, often referred to as a repeated root.
- If \(b^2 - 4ac < 0\), the equation has two complex solutions.
Solving Quadratic Equations
To solve quadratic equations like \(-x^2 + 6x + 16 = 0\), one commonly uses the quadratic formula. Here’s a step-by-step approach:
- Identify the coefficients \(a\), \(b\), and \(c\). In this equation: \(a = -1\), \(b = 6\), \(c = 16\).
- Calculate the discriminant \(b^2 - 4ac\). For this example, it is \(6^2 - 4(-1)(16) = 36 + 64 = 100\).
- Check the discriminant to determine the nature of the roots. Since \(100 > 0\), expect two different real solutions.
- Substitute back into the quadratic formula: \(x = \frac{-6 \pm \sqrt{100}}{-2}\).
- Simplify the equation by evaluating the square root and performing arithmetic operations: \(x = \frac{-6 \pm 10}{-2}\). This gives the roots: \(x = -2\) and \(x = 8\).