Chapter 16: Problem 8
For \(\boldsymbol{a}=(1,2,3), \boldsymbol{b}=(-2,3,-4), \boldsymbol{c}=(0,4,-1)\), find $$ 3 a+2 b-3 c $$
Short Answer
Expert verified
The resulting vector is \((-1, 0, 4)\).
Step by step solution
01
Understand the Expression
The given expression is a vector operation involving three vectors \( \boldsymbol{a}, \boldsymbol{b}, \boldsymbol{c} \) and involves scalar multiplication and vector addition/subtraction. We need to compute \( 3\boldsymbol{a} + 2\boldsymbol{b} - 3\boldsymbol{c} \).
02
Compute 3a
Multiply each component of the vector \( \boldsymbol{a} = (1, 2, 3) \) by 3. This yields: \[ 3\boldsymbol{a} = (3 \times 1, 3 \times 2, 3 \times 3) = (3, 6, 9) \]
03
Compute 2b
Multiply each component of the vector \( \boldsymbol{b} = (-2, 3, -4) \) by 2. This yields: \[ 2\boldsymbol{b} = (2 \times -2, 2 \times 3, 2 \times -4) = (-4, 6, -8) \]
04
Compute -3c
Multiply each component of the vector \( \boldsymbol{c} = (0, 4, -1) \) by -3. This yields: \[ -3\boldsymbol{c} = (-3 \times 0, -3 \times 4, -3 \times -1) = (0, -12, 3) \]
05
Combine the Results
Now, add the results of the previous steps together: \( 3\boldsymbol{a} + 2\boldsymbol{b} - 3\boldsymbol{c} = (3, 6, 9) + (-4, 6, -8) + (0, -12, 3) \).Compute each component separately:First component: \( 3 - 4 + 0 = -1 \)Second component: \( 6 + 6 - 12 = 0 \)Third component: \( 9 - 8 + 3 = 4 \)Thus, the resulting vector is \((-1, 0, 4)\).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Scalar Multiplication
Scalar multiplication is an operation where each component of a vector is multiplied by a scalar (a real number). This process scales the vector, which means it makes the vector longer or shorter, depending on the value of the scalar.
To perform scalar multiplication:
\[ 3 \boldsymbol{a} = (3 \times 1, 3 \times 2, 3 \times 3) = (3, 6, 9) \]
In this way, each component of \( \boldsymbol{a} \) is scaled by 3. This operation maintains the direction of the original vector, unless scaled by a negative, which reverses the direction.
To perform scalar multiplication:
- Take each component of the vector.
- Multiply each by the scalar.
- Reassemble the results into a new vector.
\[ 3 \boldsymbol{a} = (3 \times 1, 3 \times 2, 3 \times 3) = (3, 6, 9) \]
In this way, each component of \( \boldsymbol{a} \) is scaled by 3. This operation maintains the direction of the original vector, unless scaled by a negative, which reverses the direction.
Vector Addition
Vector addition involves combining the corresponding components of two vectors to form a new vector. This operation essentially "adds" the vectors together.
\[ \boldsymbol{a} + \boldsymbol{b} = (3 + (-4), 6 + 6, 9 + (-8)) = (-1, 12, 1) \]
This result represents the combination of the two vector effects in a single vector outcome.
- Start with two vectors, say \( \boldsymbol{u} = (u_1, u_2, u_3) \) and \( \boldsymbol{v} = (v_1, v_2, v_3) \).
- Add the corresponding components: \( (u_1 + v_1, u_2 + v_2, u_3 + v_3) \).
\[ \boldsymbol{a} + \boldsymbol{b} = (3 + (-4), 6 + 6, 9 + (-8)) = (-1, 12, 1) \]
This result represents the combination of the two vector effects in a single vector outcome.
Vector Subtraction
Vector subtraction works similarly to vector addition, but instead of adding, you subtract the corresponding components of the vectors.
Here’s how to perform vector subtraction:
\[ \boldsymbol{b} - \boldsymbol{c} = (-4 - 0, 6 - (-12), -8 - 3) = (-4, 18, -11) \]
This operation effectively finds the vector pointing from one to the other.
Here’s how to perform vector subtraction:
- Given two vectors \( \boldsymbol{u} = (u_1, u_2, u_3) \) and \( \boldsymbol{v} = (v_1, v_2, v_3) \).
- Subtract the components: \( (u_1 - v_1, u_2 - v_2, u_3 - v_3) \).
\[ \boldsymbol{b} - \boldsymbol{c} = (-4 - 0, 6 - (-12), -8 - 3) = (-4, 18, -11) \]
This operation effectively finds the vector pointing from one to the other.