PreCalculus Honors 1 3 Graphs of Functions HW

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Pre-Calculus Honors 1. 3: Graphs of Functions HW: p. 37 (8, 12, 14, 23

Pre-Calculus Honors 1. 3: Graphs of Functions HW: p. 37 (8, 12, 14, 23 -26 all, 38 -42 even, 80 -84 even) Copyright © Cengage Learning. All rights reserved.

Increasing and Decreasing Functions Determine the intervals on which each function is increasing, decreasing,

Increasing and Decreasing Functions Determine the intervals on which each function is increasing, decreasing, or constant. (a) (b) (c) 2

Increasing and Decreasing Functions The more you know about the graph of a function,

Increasing and Decreasing Functions The more you know about the graph of a function, the more you know about the function itself. Consider the graph shown in Figure 1. 20. Moving from left to right, this graph falls from x = – 2 to x = 0, is constant from x = 0 to x = 2, and rises from x = 2 to x = 4. Figure 1. 20 3

Even and Odd Functions • A function whose graph is symmetric with respect to

Even and Odd Functions • A function whose graph is symmetric with respect to the y -axis is an even function. • A function whose graph is symmetric with respect to the origin is an odd function. • A graph has symmetry with respect to the y-axis if whenever (x, y) is on the graph, then so is the point (–x, y). • A graph has symmetry with respect to the origin if whenever (x, y) is on the graph, then so is the point (–x, –y). • A graph has symmetry with respect to the x-axis if whenever (x, y) is on the graph, then so is the point (x, –y). 4

Even and Odd Functions A graph that is symmetric with respect to the x-axis

Even and Odd Functions A graph that is symmetric with respect to the x-axis is not the graph of a function (except for the graph of y = 0). Symmetric to y-axis. Even function. Symmetric to origin. Odd function. Symmetric to x-axis. Not a function. 5

Even and Odd Functions Algebraic Test for Even and Odd Functions: • A function

Even and Odd Functions Algebraic Test for Even and Odd Functions: • A function f is even when, for each x in the domain of f, f(-x) = f(x). • A function f is odd when, for each x in the domain of f, f(-x) = -f(x). 6

Example 10 – Even and Odd Functions Determine whether each function is even, odd,

Example 10 – Even and Odd Functions Determine whether each function is even, odd, or neither. a. g(x) = x 3 – x b. h(x) = x 2 + 1 c. f (x) = x 3 – 1 Solution: a. This function is odd because g (–x) = (–x)3+ (–x) = –x 3 + x = –(x 3 – x) = –g(x). 7

Example 10 – Solution b. h(x) = x 2 + 1 b. This function

Example 10 – Solution b. h(x) = x 2 + 1 b. This function is even because h (–x) = (–x)2 + 1 = x 2 + 1 = h (x). c. f (x) = x 3 – 1 c. Substituting –x for x produces f (–x) = (–x)3 – 1 = –x 3 – 1. So, the function is neither even nor odd. 8

Pre-Calculus Honors 1. 4: Shifting, Reflecting, and Stretching Graphs Copyright © Cengage Learning. All

Pre-Calculus Honors 1. 4: Shifting, Reflecting, and Stretching Graphs Copyright © Cengage Learning. All rights reserved. 9

Library of Parent Functions: Commonly Used Functions Label important characteristics of each parent function.

Library of Parent Functions: Commonly Used Functions Label important characteristics of each parent function. 10

Vertical Shift Change each function so it shifts up 2 units from the parent

Vertical Shift Change each function so it shifts up 2 units from the parent function. 11

Horizontal Shift Change each function so it shifts right 3 units from the parent

Horizontal Shift Change each function so it shifts right 3 units from the parent function. 12

Vertical and Horizontal Shifts 13

Vertical and Horizontal Shifts 13

Example 1 – Shifts in the Graph of a Function Compare the graph of

Example 1 – Shifts in the Graph of a Function Compare the graph of each function with the graph of f (x) = x 3. a. g (x) = x 3 – 1 b. h (x) = (x – 1)3 c. k (x) = (x + 2)3 + 1 Solution: a. You obtain the graph of g by shifting the graph of f one unit downward. Vertical shift: one unit downward Figure 1. 37(a) 14

Example 1 – Solution cont’d Compare the graph of each function with the graph

Example 1 – Solution cont’d Compare the graph of each function with the graph of f (x) = x 3. b. h (x) = (x – 1)3 : You obtain the graph of h by shifting the graph of f one unit to the right. Horizontal shift: one unit right Figure 1. 37 (b) 15

Example 1 – Solution cont’d Compare the graph of each function with the graph

Example 1 – Solution cont’d Compare the graph of each function with the graph of f (x) = x 3. c. k (x) = (x + 2)3 + 1 : You obtain the graph of k by shifting the graph of f two units to the left and then one unit upward. Two units left and one unit upward Figure 1. 37 (c) 16

Reflecting Graphs 17

Reflecting Graphs 17

Example 5 – Nonrigid Transformations Compare the graph of each function with the graph

Example 5 – Nonrigid Transformations Compare the graph of each function with the graph of f (x) = | x |. a. h (x) = 3| x | b. g (x) = | x | Solution: a. Relative to the graph of f (x) = | x |, the graph of h (x) = 3| x | = 3 f (x) is a vertical stretch (each y-value is multiplied by 3) of the graph of f (See Figure 1. 45. ) Figure 1. 45 18

Example 5 – Solution cont’d b. Similarly, the graph of g (x) = |

Example 5 – Solution cont’d b. Similarly, the graph of g (x) = | x | = f (x) is a vertical shrink (each y-value is multiplied by ) of the graph of f. (See Figure 1. 46. ) Figure 1. 46 19

Pre-Calculus Honors 1. 3: Step Functions and Piecewise-Defined Functions HW: p. 38 (56 -62

Pre-Calculus Honors 1. 3: Step Functions and Piecewise-Defined Functions HW: p. 38 (56 -62 even) Copyright © Cengage Learning. All rights reserved. 20

Example 8 – Sketching a Piecewise-Defined Function Sketch the graph of f (x) =

Example 8 – Sketching a Piecewise-Defined Function Sketch the graph of f (x) = 2 x + 3, x ≤ 1 –x + 4, x > 1 by hand. 21

Sketch the piecewise function. 22

Sketch the piecewise function. 22

Do Now: Sketch the piecewise function. 23

Do Now: Sketch the piecewise function. 23