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Ch. 2 - Graphs of the Trigonometric Functions; Inverse Trigonometric Functions
Chapter 2, Problem 23

In Exercises 17–30, determine the amplitude, period, and phase shift of each function. Then graph one period of the function.y = 1/2 sin(x + π/2)

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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, \( a = \frac{1}{2} \), so the amplitude is \( \frac{1}{2} \).
Find the period of the function using the formula \( \frac{2\pi}{b} \). Here, \( b = 1 \), so the period is \( 2\pi \).
Calculate the phase shift using \( -\frac{c}{b} \). With \( c = \frac{\pi}{2} \) and \( b = 1 \), the phase shift is \( -\frac{\pi}{2} \).
Graph one period of the function by starting at the phase shift \( -\frac{\pi}{2} \) and ending at \( -\frac{\pi}{2} + 2\pi \), marking 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 sine functions, it is determined by the coefficient in front of the sine term. For the function y = 1/2 sin(x + π/2), the amplitude is 1/2, indicating that the wave oscillates between 1/2 and -1/2.
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Period

The period of a trigonometric function is the length of one complete cycle of the wave. For sine functions, the standard period is 2π. However, if the function includes a coefficient affecting the x variable, the period is calculated as 2π divided by that coefficient. In this case, the period remains 2π since there is no coefficient affecting x.
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Phase Shift

Phase shift refers to the horizontal displacement of a wave from its standard position. It is determined by the value added or subtracted from the x variable inside the function. For y = 1/2 sin(x + π/2), the phase shift is -π/2, meaning the graph is shifted to the left by π/2 units.
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