2.2 graphing polynomial functions f - wordpress.com · · 2015-09-022015-09-02 ·...
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Pre-‐Calculus Mathematics 12 -‐ 2.2 – Graphing Polynomial Functions
Graphing a polynomial function can be summarized using the following steps:
1. Locate the zeros from factoring. (previous lesson) 2. Locate the y-‐intercept. (set x = 0 and solve for y) 3. Determine the shape at each zero from the multiplicities. (See below)
Multiplicity 1 𝒙− 𝒂 𝒏 n is even 𝒙− 𝒂 𝒏 n is odd and >1
Factor 𝑥 − 𝑎 ! 𝑥 − 𝑎 !… − 𝑥 − 𝑎 !… 𝑥 − 𝑎 !… − 𝑥 − 𝑎 !…
Graph shape at Zero
4. Determine the end behaviour using 𝒂𝒙𝒏. ( n even/odd; a > 0 or a < 0) 5. Estimate the highs and lows of the function using x values between the zeros.
(Substitute x-‐values into the original function) 6. Plot a reasonable number of points and draw a smooth continuous curve.
Example 1: Sketch: 𝑓(𝑥) = − 𝑥 + 2 ! 𝑥 − 2 !
Goals: 1. Sketch the graph of a given polynomial function 2. Sketch the graph of a polynomial function given information about the function
Pre-‐Calculus Mathematics 12 -‐ 2.2 – Graphing Polynomial Functions
Example 2: Determine the equation of the polynomial 𝑔 𝑥 in factored form, if 𝑔 −2 = −12 and the
zeros are 0, 0, –1, − 23
Example 3: Determine the equation of the polynomial in factored form.