Find The Set Of Possible Values Of $x$ For Which:1. $4x^2 - 9 \ \textless \ 0$2. $ 8 − 6 X − 5 X 2 \textgreater 0 8 - 6x - 5x^2 \ \textgreater \ 0 8 − 6 X − 5 X 2 \textgreater 0 [/tex]You Must Show All Your Working.$ \begin{array}{l} 4x^2 - 9 \ \textless \ 0 \ 4x^2
Introduction
Inequalities are mathematical expressions that compare two values using greater than (>), less than (<), greater than or equal to (≥), or less than or equal to (≤) symbols. Solving inequalities involves finding the set of possible values of the variable that satisfy the given inequality. In this article, we will focus on solving two quadratic inequalities: and . We will use algebraic techniques to find the possible values of x that satisfy each inequality.
Solving the First Inequality:
To solve the inequality , we need to find the values of x that make the expression negative. We can start by adding 9 to both sides of the inequality, which gives us:
Next, we can divide both sides of the inequality by 4, which gives us:
Now, we can take the square root of both sides of the inequality. Since we are dealing with a quadratic inequality, we need to consider both the positive and negative square roots. This gives us:
The absolute value inequality can be rewritten as a double inequality:
Therefore, the possible values of x that satisfy the inequality are all real numbers between -3/2 and 3/2.
Solving the Second Inequality:
To solve the inequality , we need to find the values of x that make the expression positive. We can start by rearranging the inequality to get:
Next, we can multiply both sides of the inequality by -1, which gives us:
Now, we can factor the quadratic expression on the left-hand side of the inequality:
To find the values of x that satisfy the inequality, we need to consider the signs of the two factors and . We can create a sign chart to help us determine the intervals where the inequality is satisfied:
Interval | |||
---|---|---|---|
- | - | + | |
- | + | - | |
+ | + | + |
From the sign chart, we can see that the inequality is satisfied when . Therefore, the possible values of x that satisfy the inequality are all real numbers between -2 and 4/5.
Conclusion
In this article, we solved two quadratic inequalities: and . We used algebraic techniques to find the possible values of x that satisfy each inequality. For the first inequality, we found that the possible values of x are all real numbers between -3/2 and 3/2. For the second inequality, we found that the possible values of x are all real numbers between -2 and 4/5. We hope that this article has provided a clear and concise explanation of how to solve quadratic inequalities.
References
- [1] Larson, R. (2014). College Algebra. Cengage Learning.
- [2] Rogawski, J. (2011). Calculus. W.H. Freeman and Company.
- [3] Stewart, J. (2011). Calculus. Cengage Learning.
Keywords
- Quadratic inequalities
- Algebraic techniques
- Inequality solutions
- Possible values of x
- Real numbers
- Double inequality
- Absolute value inequality
- Sign chart
- Quadratic expression
- Factoring
- Algebraic manipulation
Introduction
Quadratic inequalities are mathematical expressions that compare two values using greater than (>), less than (<), greater than or equal to (≥), or less than or equal to (≤) symbols. Solving quadratic inequalities involves finding the set of possible values of the variable that satisfy the given inequality. In this article, we will provide a Q&A guide to help you understand how to solve quadratic inequalities.
Q: What is a quadratic inequality?
A: A quadratic inequality is a mathematical expression that compares two values using greater than (>), less than (<), greater than or equal to (≥), or less than or equal to (≤) symbols, where the variable is raised to the power of 2.
Q: How do I solve a quadratic inequality?
A: To solve a quadratic inequality, you need to follow these steps:
- Rearrange the inequality to get the quadratic expression on one side of the inequality sign.
- Factor the quadratic expression, if possible.
- Create a sign chart to determine the intervals where the inequality is satisfied.
- Identify the possible values of x that satisfy the inequality.
Q: What is a sign chart?
A: A sign chart is a table that shows the signs of the factors of the quadratic expression in different intervals. It helps you determine the intervals where the inequality is satisfied.
Q: How do I create a sign chart?
A: To create a sign chart, you need to:
- Identify the critical points of the quadratic expression, which are the values of x that make the quadratic expression equal to zero.
- Create a table with the intervals between the critical points.
- Determine the signs of the factors of the quadratic expression in each interval.
- Use the signs of the factors to determine the intervals where the inequality is satisfied.
Q: What are the critical points of a quadratic expression?
A: The critical points of a quadratic expression are the values of x that make the quadratic expression equal to zero. They are the roots of the quadratic equation.
Q: How do I find the roots of a quadratic equation?
A: To find the roots of a quadratic equation, you can use the quadratic formula:
where a, b, and c are the coefficients of the quadratic equation.
Q: What is the quadratic formula?
A: The quadratic formula is a mathematical formula that gives the roots of a quadratic equation. It is used to solve quadratic equations of the form ax^2 + bx + c = 0.
Q: Can I use the quadratic formula to solve quadratic inequalities?
A: No, the quadratic formula is used to solve quadratic equations, not quadratic inequalities. To solve quadratic inequalities, you need to use the steps outlined above.
Q: What are some common mistakes to avoid when solving quadratic inequalities?
A: Some common mistakes to avoid when solving quadratic inequalities include:
- Not rearranging the inequality to get the quadratic expression on one side of the inequality sign.
- Not factoring the quadratic expression, if possible.
- Not creating a sign chart to determine the intervals where the inequality is satisfied.
- Not identifying the possible values of x that satisfy the inequality.
Q: How do I check my solution to a quadratic inequality?
A: To check your solution to a quadratic inequality, you need to:
- Plug in a value of x from each interval into the original inequality.
- Check if the inequality is satisfied for each value of x.
- If the inequality is satisfied for all values of x in the interval, then the solution is correct.
Conclusion
Quadratic inequalities are mathematical expressions that compare two values using greater than (>), less than (<), greater than or equal to (≥), or less than or equal to (≤) symbols. Solving quadratic inequalities involves finding the set of possible values of the variable that satisfy the given inequality. In this article, we provided a Q&A guide to help you understand how to solve quadratic inequalities. We hope that this article has provided a clear and concise explanation of how to solve quadratic inequalities.
References
- [1] Larson, R. (2014). College Algebra. Cengage Learning.
- [2] Rogawski, J. (2011). Calculus. W.H. Freeman and Company.
- [3] Stewart, J. (2011). Calculus. Cengage Learning.
Keywords
- Quadratic inequalities
- Algebraic techniques
- Inequality solutions
- Possible values of x
- Real numbers
- Double inequality
- Absolute value inequality
- Sign chart
- Quadratic expression
- Factoring
- Algebraic manipulation
- Quadratic formula
- Roots of a quadratic equation
- Critical points
- Intervals
- Inequality satisfaction