Find the zeros for each polynomial function and give the multiplicity for each zero. State whether the graph crosses the x-axis, or touches the x-axis and turns around, at each zero. f(x)=−3(x+1/2)(x−4)3
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- 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
Understanding Polynomial Functions
Problem 32
Textbook Question
Graph each polynomial function. Factor first if the polynomial is not in factored form. ƒ(x)=-x(x+1)(x-1)
Verified step by step guidance1
Identify the given polynomial function: \(f(x) = -x(x+1)(x-1)\). Notice that it is already factored into three linear factors.
Recognize the zeros of the function by setting each factor equal to zero: \(x = 0\), \(x + 1 = 0 \Rightarrow x = -1\), and \(x - 1 = 0 \Rightarrow x = 1\). These are the x-intercepts of the graph.
Determine the end behavior of the polynomial. Since the leading term comes from multiplying \(-x\), \(x\), \(x+1\), and \(x-1\), the degree is 3 (odd degree) and the leading coefficient is negative, so as \(x \to \infty\), \(f(x) \to -\infty\), and as \(x \to -\infty\), \(f(x) \to \infty\).
Plot the zeros on the x-axis at \(x = -1\), \$0\(, and \)1\(. Then, choose a test point in each interval determined by these zeros to find the sign of \)f(x)$ in those intervals, which helps to sketch the curve between the intercepts.
Use the information about zeros, end behavior, and test points to sketch the graph of \(f(x)\). Remember the graph crosses the x-axis at each zero because each factor is to the first power.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Factoring Polynomial Functions
Factoring involves expressing a polynomial as a product of its factors, which simplifies analysis and graphing. For example, the given function is already factored as -x(x+1)(x-1), showing its roots clearly. Factoring helps identify zeros and simplifies evaluating the function.
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Introduction to Factoring Polynomials
Zeros of a Polynomial Function
Zeros are the values of x where the polynomial equals zero, found by setting each factor equal to zero. For ƒ(x) = -x(x+1)(x-1), the zeros are x = 0, -1, and 1. These points are where the graph crosses or touches the x-axis, crucial for sketching the graph.
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Finding Zeros & Their Multiplicity
End Behavior of Polynomial Functions
End behavior describes how the graph behaves as x approaches positive or negative infinity, determined by the leading term's degree and sign. Here, the leading term is -x³, so as x → ±∞, ƒ(x) → ∓∞, meaning the graph falls to the right and rises to the left. Understanding this guides the overall shape of the graph.
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End Behavior of Polynomial Functions
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