Chapter 1: Problem 64
Use the discriminant to determine the number of real solutions of the equation. Do not solve the equation. \(x^{2}+2.21 x+1.21=0\)
Short Answer
Expert verified
The equation has 2 distinct real solutions.
Step by step solution
01
Identify the coefficients
The given quadratic equation is \(x^{2} + 2.21x + 1.21 = 0\). Here, \(a = 1\), \(b = 2.21\), and \(c = 1.21\).
02
Write the discriminant formula
The discriminant of a quadratic equation in the form \(ax^2 + bx + c = 0\) is given by the formula \(D = b^2 - 4ac\).
03
Substitute values into the discriminant formula
Substitute \(b = 2.21\), \(a = 1\), and \(c = 1.21\) into the discriminant formula: \(D = (2.21)^2 - 4(1)(1.21)\).
04
Calculate the discriminant
First, calculate \((2.21)^2 = 4.8841\). Then calculate \(4 \times 1 \times 1.21 = 4.84\). Therefore, the discriminant \(D = 4.8841 - 4.84 = 0.0441\).
05
Determine the number of real solutions
Since the discriminant \(D = 0.0441\) is greater than zero, the quadratic equation has 2 distinct real solutions.
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Understanding Quadratic Equations
Quadratic equations are a fundamental concept in algebra, defining any polynomial equation of the form \( ax^2 + bx + c = 0 \). These equations represent parabolic curves when plotted on a graph. The 'quadratic' term arises because the highest degree of the variable, usually \( x \), is squared. This makes them slightly more complex than linear equations, but they can always be solved using consistent methods. Key components of a quadratic equation are:
- \( a \), the quadratic coefficient, which cannot be zero.
- \( b \), the linear coefficient.
- \( c \), the constant term.
Number of Real Solutions in Quadratic Equations
The number of real solutions a quadratic equation possesses depends on the value of its discriminant. The discriminant, denoted as \( D \), is calculated using the formula \( D = b^2 - 4ac \). This specific value tells you whether the parabola will intersect the \( x \)-axis and how many times.Here are the scenarios:
- If \( D > 0 \), there are 2 distinct real solutions. The parabola crosses the \( x \)-axis at two points.
- If \( D = 0 \), there is exactly 1 real solution, also called a repeated or double root. The parabola just touches the \( x \)-axis.
- If \( D < 0 \), there are no real solutions. The parabola does not cross the \( x \)-axis, and the solutions are complex numbers.
Calculating Discriminants
Calculating the discriminant of a quadratic equation is a straightforward process if done step by step. For the equation example \( x^2 + 2.21x + 1.21 = 0 \), you need to:1. Identify the coefficients: \( a = 1 \), \( b = 2.21 \), and \( c = 1.21 \). 2. Apply these values to the discriminant formula: \( D = b^2 - 4ac \).3. Substitute the coefficients into the formula: \( D = (2.21)^2 - 4 \times 1 \times 1.21 \).4. Perform the calculations:
- First, calculate \( (2.21)^2 = 4.8841 \).
- Next, calculate \( 4 \times 1.21 = 4.84 \).
- Subtract these results to get \( D = 4.8841 - 4.84 = 0.0441 \).