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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 43c

Given vectors u and v, find: v - 3u. 
u = 〈-1, 2〉, v = 〈3, 0〉

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Identify the given vectors: \( \mathbf{u} = \langle -1, 2 \rangle \) and \( \mathbf{v} = \langle 3, 0 \rangle \).
Understand that the expression \( \mathbf{v} - 3\mathbf{u} \) means you need to multiply vector \( \mathbf{u} \) by the scalar 3, then subtract the resulting vector from \( \mathbf{v} \).
Calculate the scalar multiplication: multiply each component of \( \mathbf{u} \) by 3, which gives \( 3 \mathbf{u} = \langle 3 \times (-1), 3 \times 2 \rangle = \langle -3, 6 \rangle \).
Perform the vector subtraction by subtracting the corresponding components of \( 3\mathbf{u} \) from \( \mathbf{v} \): \( \mathbf{v} - 3\mathbf{u} = \langle 3 - (-3), 0 - 6 \rangle \).
Simplify the subtraction inside the components to get the resulting vector.

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주요 개념

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

Vector Representation

Vectors are quantities defined by both magnitude and direction, often represented as ordered pairs or tuples in coordinate form, such as u = 〈x, y〉. Understanding how to interpret these components is essential for performing operations like addition, subtraction, and scalar multiplication.
추천 영상:
03:48
Introduction to Vectors

Scalar Multiplication of Vectors

Scalar multiplication involves multiplying each component of a vector by a real number (scalar). For example, multiplying vector u = 〈x, y〉 by scalar 3 results in 〈3x, 3y〉. This operation changes the vector's magnitude but not its direction unless the scalar is negative.
추천 영상:
05:05
Multiplying Vectors By Scalars

Vector Addition and Subtraction

Adding or subtracting vectors is done component-wise: for vectors a = 〈a1, a2〉 and b = 〈b1, b2〉, a ± b = 〈a1 ± b1, a2 ± b2〉. This principle allows combining vectors or finding the difference between them, which is crucial for solving expressions like v - 3u.
추천 영상:
05:29
Adding Vectors Geometrically