CURVE SKETCHING Section 3 6 Calculus APDual Revised



























































- Slides: 59
CURVE SKETCHING Section 3. 6 Calculus AP/Dual, Revised © 2013 viet. dang@humble. k 12. tx. us 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 1
REVIEW Given f(x) = x 4 – 4 x 3, find the relative extrema 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 2
REVIEW Given f(x) = x 4 – 4 x 3, find the absolute extrema from [– 1, 1] 1/12/2022 5: 26 AM 3. 6 – Curve Sketching x y – 1 5 0 0 1 – 3 3
10 KEYS TO GRAPHING FUNCTIONS A. B. C. D. E. F. G. H. I. x–intercept (let y = 0) y–intercept (let x = 0) Symmetry Vertical Asymptotes (let Denominator equal to 0) and Horizontal Asymptotes (B/S = Slant Asymptote, S/B = 0, Same: “Co”) Identify all Critical Values First Derivative and Second Derivative Chart with justification Identify all relative/local and absolute maximums and minimums Identify all concavity Domain (interval notation) and Range in Interval Notation Graphs with appropriate scale with labeled f(x), f '(x), and f "(x) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 4
GUIDELINES OF ANALYZING A GRAPH A. B. C. D. E. F. G. Determine domain and range Find f '(x) and f ''(x) Find the critical numbers of f, and identify the function's behavior at each one Find where the curve is increasing and decreasing Find the points of inflection, if any, and determine concavity of curve Identify any asymptotes Plot key points, such as intercepts and points 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 5
REVIEW A. First Derivative Test 1. Positive: Curve is Rising 2. Negative: Curve is Falling 3. Zero: Local/Relative Minimum or Maximum B. Second Derivative Test with Critical Values 1. Positive: Concave Up 2. Negative: Concave Down 3. Zero: Go back to the First Derivative Test 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 6
CONCAVE UP OR CONCAVE DOWN 1/12/2022 5: 26 AM 3. 4 – Concavity and Second Derivative Test 7
EXAMPLE 1 The graph of function f(x) is given. Establish the x and y–intercept(s), critical numbers, possible points of inflection, increasing and decreasing intervals, and concave intervals. X-intercept(s): Y-intercept(s): Critical Numbers: Relative Max Relative Min Increasing Intervals: Decreasing Intervals: Points of Inflection: (Changes Concavity) Concave Up: 1/12/2022 5: 26 AM Concave Down: 3. 6 – Curve Sketching 8
EXAMPLE 2 The graph of function f(x) is given. Establish the x and y–intercept(s), critical numbers, possible points of inflection, increasing and decreasing intervals, and concave intervals. Then, Sketch the derivative of this graph. X-intercept(s): Y-intercept(s): Critical Numbers: Relative Max Relative Min Increasing Intervals: Decreasing Intervals: Points of Inflection: (Changes Concavity) Concave Up: Concave Down: 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 9
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 10
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 11
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 12
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 13
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 14
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 15
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 16
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 17
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. x (–∞, 0) x=0 (0, 2) x=2 (2, ∞) f(x) f’(x) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 18
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. (–∞, 0) 1/12/2022 5: 26 AM x=0 (0, 2) 3. 6 – Curve Sketching x=2 (2, ∞) 19
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. (–∞, 0) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 20
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. (0, 2) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 21
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. (2, ∞) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 22
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. x (–∞, 0) x=0 (0, 2) x=2 (2, ∞) f(x) f’(x) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 23
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. x (–∞, 1) x=1 (1, ∞) f(x) f’’(x) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 24
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. (–∞, 1) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 25
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. (1, ∞) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 26
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. x (–∞, 1) x=1 (1, ∞) f(x) f’’(x) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 27
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. x (–∞, 0) x=0 (0, 2) x=2 (2, ∞) f(x) f’(x) x (–∞, 1) x=1 (1, ∞) f(x) f’’(x) 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 28
EXAMPLE 3 Sketch f(x) = x 3 – 3 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 29
EXAMPLE 4 Sketch f(x) = x 4 – 2 x 2. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. X-intercept(s): Y-intercept(s): Critical Numbers: Relative Max Relative Min Increasing Intervals: Decreasing Intervals: Points of Inflection: (Changes Concavity) Concave Up: Concave Down: 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 30
YOUR TURN Sketch f(x) = 3 x 3 – 9 x + 1. Establish the x and y–intercept(s), vertical and horizontal asymptotes, critical numbers, possible points of inflection, domain, symmetry, and test intervals. You can use your calculator for the x-int. 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 31
EXAMPLE 5 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 32
EXAMPLE 5 1/12/2022 5: 26 AM 3. 6 – Curve Sketching 33
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 34
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 35
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 36
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 37
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 38
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 39
EXAMPLE 5 x (–∞, – 2) x = – 2 (– 2, 0) x=0 (0, 2) x=2 (2, ∞) f(x) f’(x) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 40
EXAMPLE 5 (–∞, – 2) 1/12/2022 5: 27 AM (– 2, 0) 3. 6 – Curve Sketching (0, 2) (2, ∞) 41
EXAMPLE 5 (–∞, – 2) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 42
EXAMPLE 5 (– 2, 0) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 43
EXAMPLE 5 (0, 2) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 44
EXAMPLE 5 (2, ∞) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 45
EXAMPLE 5 x (–∞, – 2) x = – 2 (– 2, 0) x=0 (0, 2) x=2 (2, ∞) f(x) f’(x) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 46
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 47
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 48
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 49
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 50
EXAMPLE 5 x (–∞, – 2) x = – 2 (– 2, 0) x=0 (0, 2) x=2 (2, ∞) f’(x) f’’(x) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 51
EXAMPLE 5 (–∞, – 2) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 52
EXAMPLE 5 (– 2, 0) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 53
EXAMPLE 5 (0, 2) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 54
EXAMPLE 5 (2, ∞) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 55
EXAMPLE 5 x (–∞, – 2) x = – 2 (– 2, 0) x=0 (0, 2) x=2 (2, ∞) f’(x) f’’(x) 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 56
EXAMPLE 5 1/12/2022 5: 27 AM 3. 6 – Curve Sketching 57
YOUR TURN X-intercept(s): Y-intercept(s): Horizontal Asy. : Vertical Asymptote: Critical Numbers: Increasing Intervals: Decreasing Intervals: Points of Inflection: (Changes Concavity) Concave Up: Concave Down: 1/12/2022 5: 28 AM 3. 6 – Curve Sketching 58
ASSIGNMENT Curve Sketching Worksheet 1/12/2022 5: 28 AM 3. 6 – Curve Sketching 59