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Ch. 4 - Laws of Sines and Cosines; Vectors
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601당신이 사용하는 게 아니라요?교과서 변경
4장, 문제 44

In Exercises 39–46, find the unit vector that has the same direction as the vector v.


v = 4i - 2j

검증된 단계별 안내
1
Identify the given vector \( \mathbf{v} = 4\mathbf{i} - 2\mathbf{j} \). This means the vector has components \( (4, -2) \).
Calculate the magnitude (length) of the vector \( \mathbf{v} \) using the formula: \[ \|\mathbf{v}\| = \sqrt{(4)^2 + (-2)^2} \]
Simplify the expression under the square root to find the magnitude: \[ \|\mathbf{v}\| = \sqrt{16 + 4} \]
Find the unit vector \( \mathbf{u} \) in the same direction as \( \mathbf{v} \) by dividing each component of \( \mathbf{v} \) by its magnitude: \[ \mathbf{u} = \left( \frac{4}{\|\mathbf{v}\|}, \frac{-2}{\|\mathbf{v}\|} \right) \]
Express the unit vector in terms of the standard unit vectors \( \mathbf{i} \) and \( \mathbf{j} \): \[ \mathbf{u} = \frac{4}{\|\mathbf{v}\|} \mathbf{i} - \frac{2}{\|\mathbf{v}\|} \mathbf{j} \]

비슷한 문제에 대한 검증된 영상 답변:

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 Components

A vector in two dimensions can be expressed in terms of its components along the x and y axes, typically written as v = ai + bj, where a and b are scalar values. Understanding these components is essential for operations like finding magnitude and direction.
추천 영상:
03:55
Position Vectors & Component Form

Magnitude of a Vector

The magnitude (or length) of a vector v = ai + bj is calculated using the Pythagorean theorem as √(a² + b²). This scalar value represents the distance from the origin to the point defined by the vector components.
추천 영상:
04:44
Finding Magnitude of a Vector

Unit Vector

A unit vector has a magnitude of 1 and points in the same direction as the original vector. It is found by dividing each component of the vector by its magnitude, effectively normalizing the vector without changing its direction.
추천 영상:
04:04
Unit Vector in the Direction of a Given Vector