Determine whether each statement is true or false. If false, explain why. The product of a complex number and its conjugate is always a real number.
Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
4. Polynomial Functions
Zeros of Polynomial Functions
Problem 16
Textbook Question
Find the zeros for each polynomial function and give the multiplicity of each zero. State whether the graph crosses the x-axis, or touches the x-axis and turns around, at each zero.
Verified step by step guidance1
Identify the zeros of the polynomial by setting each factor equal to zero: solve \(x - 1 = 0\), \(x + 2 = 0\), and \(x + 5 = 0\) to find the zeros.
Determine the multiplicity of each zero by looking at the exponent on each factor: the factor \((x - 1)\) has multiplicity 1, \((x + 2)^2\) has multiplicity 2, and \((x + 5)^2\) has multiplicity 2.
Recall that if a zero has an odd multiplicity, the graph crosses the x-axis at that zero; if the multiplicity is even, the graph touches the x-axis and turns around at that zero.
Summarize the behavior at each zero: for \(x = 1\) (multiplicity 1), the graph crosses the x-axis; for \(x = -2\) and \(x = -5\) (both multiplicity 2), the graph touches and turns around at the x-axis.
Combine all this information to describe the zeros, their multiplicities, and the behavior of the graph at each zero.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
3mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Zeros of a Polynomial Function
Zeros of a polynomial are the values of x that make the function equal to zero. They correspond to the x-intercepts of the graph. To find zeros, set the polynomial equal to zero and solve for x, often by factoring or using given factored form.
Recommended video:
Finding Zeros & Their Multiplicity
Multiplicity of Zeros
Multiplicity refers to how many times a particular zero appears as a factor in the polynomial. If a zero has even multiplicity, the graph touches the x-axis and turns around at that zero. If the multiplicity is odd, the graph crosses the x-axis at that zero.
Recommended video:
Finding Zeros & Their Multiplicity
Behavior of Graph at Zeros
The graph's behavior at each zero depends on the zero's multiplicity. For odd multiplicity, the graph crosses the x-axis, indicating a sign change. For even multiplicity, the graph only touches the axis and reverses direction, showing no sign change.
Recommended video:
Identifying Intervals of Unknown Behavior
Related Videos
Related Practice
Textbook Question
375
views
