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Ch. 2 - Graphs of the Trigonometric Functions; Inverse Trigonometric Functions
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601Not the one you use?Change textbook
Chapter 2, Problem 21

In Exercises 17–30, determine the amplitude, period, and phase shift of each function. Then graph one period of the function.y = 3 sin(2x − π)

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Identify the standard form of the sine function: \( y = a \sin(bx - c) + d \).
Determine the amplitude by identifying the coefficient \( a \). In this case, \( a = 3 \), so the amplitude is \( |3| = 3 \).
Find the period of the function using the formula \( \frac{2\pi}{b} \). Here, \( b = 2 \), so the period is \( \frac{2\pi}{2} = \pi \).
Calculate the phase shift using \( \frac{c}{b} \). Here, \( c = \pi \) and \( b = 2 \), so the phase shift is \( \frac{\pi}{2} \). Since the expression is \( bx - c \), the shift is to the right.
Graph one period of the function by starting at the phase shift \( \frac{\pi}{2} \) and using the period \( \pi \) to determine the end of one cycle. Plot key points such as maximum, minimum, and intercepts based on the amplitude and period.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Amplitude

Amplitude refers to the maximum height of a wave from its midline. In the context of the sine function, it is determined by the coefficient in front of the sine term. For the function y = 3 sin(2x − π), the amplitude is 3, indicating that the wave oscillates 3 units above and below the midline.
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Period

The period of a trigonometric function is the length of one complete cycle of the wave. For the sine function, the period can be calculated using the formula 2π divided by the coefficient of x inside the sine function. In this case, the period of y = 3 sin(2x − π) is π, meaning the function completes one full cycle over an interval of π units.
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Phase Shift

Phase shift refers to the horizontal shift of the graph of a trigonometric function. It is determined by the constant added or subtracted from the x variable inside the function. For y = 3 sin(2x − π), the phase shift can be calculated as π/2, indicating that the graph is shifted π/2 units to the right from the origin.
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