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Ch. 7 - Applications of Trigonometry and Vectors
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161당신이 사용하는 게 아니라요?교과서 변경
8장, 문제 12

Find the magnitude and direction angle for each vector. Round angle measures to the nearest tenth, as necessary. See Example 1.
〈-7, 24〉

검증된 단계별 안내
1
Identify the components of the vector given as \( \langle -7, 24 \rangle \), where \( x = -7 \) and \( y = 24 \).
Calculate the magnitude of the vector using the formula \( \text{magnitude} = \sqrt{x^2 + y^2} \). Substitute the values to get \( \sqrt{(-7)^2 + 24^2} \).
Find the direction angle \( \theta \) of the vector relative to the positive x-axis using the formula \( \theta = \tan^{-1} \left( \frac{y}{x} \right) \). Substitute the values to get \( \theta = \tan^{-1} \left( \frac{24}{-7} \right) \).
Since the x-component is negative and the y-component is positive, the vector lies in the second quadrant. Adjust the angle \( \theta \) accordingly by adding 180 degrees if necessary to find the correct direction angle.
Round the direction angle to the nearest tenth of a degree as required.

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

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

Vector Magnitude

The magnitude of a vector represents its length and is calculated using the Pythagorean theorem. For a vector 〈x, y〉, the magnitude is √(x² + y²). This gives a non-negative scalar value indicating the vector's size regardless of direction.
추천 영상:
04:44
Finding Magnitude of a Vector

Direction Angle of a Vector

The direction angle of a vector is the angle it makes with the positive x-axis, measured counterclockwise. It can be found using the inverse tangent function: θ = arctan(y/x). Adjustments may be needed based on the vector's quadrant to get the correct angle.
추천 영상:
05:13
Finding Direction of a Vector

Quadrant Considerations in Angle Calculation

Since arctan(y/x) only returns values between -90° and 90°, the vector's quadrant must be considered to determine the correct direction angle. For vectors in quadrants II, III, or IV, add 180° or 360° as needed to place the angle in the correct range (0° to 360°).
추천 영상:
6:36
Quadratic Formula