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Ch. 2 - Graphs of the Trigonometric Functions; Inverse Trigonometric Functions
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601당신이 사용하는 게 아니라요?교과서 변경
2장, 문제 44

Determine the amplitude, period, and phase shift of each function. Then graph one period of the function.
y = cos(x + π/2)

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1
Identify the general form of the cosine function: \(y = A \cos(B(x - C))\), where \(A\) is the amplitude, \(\frac{2\pi}{B}\) is the period, and \(C\) is the phase shift.
Rewrite the given function \(y = \cos(x + \frac{\pi}{2})\) in the form \(y = \cos(x - (-\frac{\pi}{2}))\) to clearly identify the phase shift.
Determine the amplitude \(A\) by looking at the coefficient in front of the cosine function. Here, since there is no coefficient, \(A = 1\).
Calculate the period using the formula \(\text{Period} = \frac{2\pi}{B}\). Since the coefficient of \(x\) is 1, \(B = 1\), so the period is \(2\pi\).
Find the phase shift \(C\) from the expression inside the cosine. Since it is \(x - (-\frac{\pi}{2})\), the phase shift is \(-\frac{\pi}{2}\), meaning the graph shifts to the left by \(\frac{\pi}{2}\) units.

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
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7m
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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Amplitude of a Trigonometric Function

Amplitude is the maximum absolute value of a trigonometric function, representing the height from the midline to the peak. For functions like y = cos(x), the amplitude is the coefficient before the cosine term. In y = cos(x + π/2), the amplitude is 1, since there is no coefficient other than 1.
추천 영상:
6:04
Introduction to Trigonometric Functions

Period of a Trigonometric Function

The period is the length of one complete cycle of the function, calculated as 2π divided by the coefficient of x inside the function. For y = cos(bx + c), the period is 2π/|b|. In y = cos(x + π/2), since b = 1, the period remains 2π.
추천 영상:
5:33
Period of Sine and Cosine Functions

Phase Shift of a Trigonometric Function

Phase shift is the horizontal translation of the graph, determined by solving (bx + c) = 0 for x. It equals -c/b, indicating how far the graph shifts left or right. For y = cos(x + π/2), the phase shift is -π/2, meaning the graph shifts π/2 units to the left.
추천 영상:
6:31
Phase Shifts