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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 31

In Exercises 21–38, let u = 2i - 5j, v = -3i + 7j, and w = -i - 6j. Find each specified vector or scalar.
3w + 2v

검증된 단계별 안내
1
Identify the given vectors: \( \mathbf{u} = 2\mathbf{i} - 5\mathbf{j} \), \( \mathbf{v} = -3\mathbf{i} + 7\mathbf{j} \), and \( \mathbf{w} = -\mathbf{i} - 6\mathbf{j} \).
Calculate the scalar multiplication of vector \( \mathbf{w} \) by 3: multiply each component of \( \mathbf{w} \) by 3, resulting in \( 3\mathbf{w} = 3(-\mathbf{i}) + 3(-6\mathbf{j}) \).
Calculate the scalar multiplication of vector \( \mathbf{v} \) by 2: multiply each component of \( \mathbf{v} \) by 2, resulting in \( 2\mathbf{v} = 2(-3\mathbf{i}) + 2(7\mathbf{j}) \).
Add the resulting vectors from the previous two steps component-wise: add the \( \mathbf{i} \) components together and the \( \mathbf{j} \) components together to find \( 3\mathbf{w} + 2\mathbf{v} \).
Write the final vector in the form \( a\mathbf{i} + b\mathbf{j} \), where \( a \) and \( b \) are the sums of the respective components.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
2m

주요 개념

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

Vector Representation in Component Form

Vectors in two dimensions can be expressed as a combination of unit vectors i and j, representing the x and y components respectively. For example, u = 2i - 5j means the vector has an x-component of 2 and a y-component of -5. Understanding this form allows for straightforward vector addition and scalar multiplication.
추천 영상:
03:55
Position Vectors & Component Form

Scalar Multiplication of Vectors

Scalar multiplication involves multiplying each component of a vector by a scalar (a real number). For instance, multiplying vector w by 3 means multiplying both its i and j components by 3, resulting in a new vector scaled in magnitude but with the same direction if the scalar is positive.
추천 영상:
05:05
Multiplying Vectors By Scalars

Vector Addition

Vector addition is performed by adding corresponding components of two vectors. For example, adding 2v and 3w requires adding the x-components of 2v and 3w together, and similarly for the y-components, resulting in a new vector that combines both directions and magnitudes.
추천 영상:
05:29
Adding Vectors Geometrically