Skip to main content
Ch. 6 - Inverse Circular Functions and Trigonometric Equations
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161당신이 사용하는 게 아니라요?교과서 변경
7장, 문제 11

Solve each equation for x, where x is restricted to the given interval.
y = 6 cos x/4 , for x in [0, 4π]

검증된 단계별 안내
1
Identify the given equation: \(y = 6 \cos \frac{x}{4}\), and the interval for \(x\) is \([0, 4\pi]\).
Since the equation is in terms of \(y\), decide what value of \(y\) you want to solve for. For example, if you want to find \(x\) when \(y\) equals a specific value, set \(6 \cos \frac{x}{4} = y_0\) where \(y_0\) is that value.
Isolate the cosine term by dividing both sides by 6: \(\cos \frac{x}{4} = \frac{y_0}{6}\).
Use the inverse cosine function to solve for \(\frac{x}{4}\): \(\frac{x}{4} = \arccos \left( \frac{y_0}{6} \right)\).
Multiply both sides by 4 to solve for \(x\): \(x = 4 \arccos \left( \frac{y_0}{6} \right)\). Remember to consider all solutions for \(x\) within the interval \([0, 4\pi]\) by using the periodicity and symmetry of the cosine function.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
도움이 되었나요?

주요 개념

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

Solving Trigonometric Equations

Solving trigonometric equations involves finding all values of the variable that satisfy the equation within a specified interval. This often requires isolating the trigonometric function and using inverse functions or known values of sine, cosine, or tangent to determine solutions.
추천 영상:
4:34
How to Solve Linear Trigonometric Equations

Properties of the Cosine Function

The cosine function is periodic with a period of 2π, meaning its values repeat every 2π units. Understanding its graph, symmetry, and key values helps in identifying all solutions within a given interval, especially when the argument of cosine is scaled or shifted.
추천 영상:
5:53
Graph of Sine and Cosine Function

Interval Restrictions and Domain Considerations

When solving equations on a restricted interval, it is essential to consider only solutions that lie within that domain. This involves adjusting for the function's period and ensuring that all valid solutions for x fall within the specified range, such as [0, 4π] in this problem.
추천 영상:
3:43
Finding the Domain of an Equation