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Algebra 2: Notes 5.2:. Evaluate and graph polynomial functions. GOALS: “”. End Behavior of Polynomials:. Disco Fever for odd degree. YMCA for even degree. Leading Coefficient: Positive Negative Positive Negative.
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Algebra 2: Notes 5.2: Evaluate and graph polynomial functions. GOALS: “” End Behavior of Polynomials: Disco Fever for odd degree YMCA for even degree Leading Coefficient: Positive Negative Positive Negative • Zeros of Polynomials: If P is a polynomial and if c is a number such that P(c)=0, then we say c is a zero of P. • c is a zero of P • x=c is a root of the equation P(x)=0 • (x-c) is a factor of P(x).
Algebra 2: Notes 5.2: • Guidelines for Graphing Polynomial Functions: • Zeros: Factor the polynomial to find all its zeros; these are the x-intercepts of the graph. • Test Points: Make x-y table. Include values to determine if graph lies above or below x-axis. Include y-intercept in table. • End Behavior: Determine the end behavior of the polynomial. • Graph: Plot intercepts and other points from table. Sketch a smooth curve that passes through these points and exhibits the required end behavior.
5.2 Example 1: Polynomial function? End behavior? 5.2 Example 2: Graph the polynomial function. Check powers. All need to be positive and integers. Power of 2.5 makes it not a polynomial. Polynomial, and highest power is 4 so it is a 4th degree polynomial or quartic. 1st Factor if you can. 2nd Decide if Disco or YMCA type graph. 2nd Plug in x values and find y. 3rd Plot points. Disco Fever graph since it is odd and left side goes up while right goes down since leading coefficient is negative.
5.2 Example 3: Synthetic division. Use synthetic division to evaluate the function when x=2. Synthetic Division: For dividing by x-c. Place c on the ledge. Put coefficients of the polynomial in row (keep the sign with the number). Bring down 1st number. Times c by the number brought down. Place result under next number. Add the result. Then repeat till last number.