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Shlok Kumar
Shlok Kumar

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Vector Algebra

Vector algebra is a branch of mathematics that deals with vectors—quantities that have both magnitude and direction. It plays a crucial role in various fields such as physics, engineering, and computer science. Understanding vector algebra is essential for solving problems in multiple dimensions, particularly those involving direction and magnitude.

Key Vector Operations

Vectors cannot be added or manipulated using standard arithmetic rules. Instead, vector operations are defined specifically for these quantities. Here are some key vector operations:

  1. Addition of Two Vectors
  2. Subtraction of Two Vectors
  3. Multiplication of a Vector with a Scalar
  4. Dot Product
  5. Cross Product

1. Addition of Vectors

When adding two vectors, both their magnitudes and directions must be considered. The Triangle Law of vector addition states that if two vectors are represented as two sides of a triangle, the sum of these vectors is given by the third side.

a + b = c
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The commutative property applies here, meaning:

a + b = b + a
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Triangle Law of Vector Addition

In a triangle formed by vectors ( a ) and ( b ), the resultant vector ( c ) can be represented as:

|c| = √(|a|² + |b|² + 2|a||b|cos(θ))
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Where ( θ ) is the angle between the two vectors.

Parallelogram Law of Vector Addition

According to the Parallelogram Law, if two vectors represent adjacent sides of a parallelogram, then the diagonal from the same initial point represents the resultant vector.

2. Subtraction of Two Vectors

Subtraction can be achieved using vector addition rules. A negative vector is simply a vector with the opposite direction. The Triangle Law can be applied to find the resultant vector.

3. Multiplication of Vectors with a Scalar

When a vector ( a ) is multiplied by a scalar ( k ), the direction remains the same while the magnitude is scaled by ( k ).

|ka| = k|a|
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If ( k > 1 ), the magnitude increases; if ( k < 1 ), the magnitude decreases.

4. Dot Product (Scalar Product)

The dot product of two vectors ( A ) and ( B ) is defined as:

A · B = |A||B|cos(θ)
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If the vectors are represented in component form:

a = a₁i + a₂j + a₃k
b = b₁i + b₂j + b₃k
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The dot product becomes:

a · b = a₁b₁ + a₂b₂ + a₃b₃
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5. Cross Product (Vector Product)

The cross product of two vectors ( A ) and ( B ) is denoted as ( A × B ). The resulting vector is perpendicular to both original vectors, and its magnitude is given by:

|A × B| = |A||B|sin(θ)
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The direction is determined by the right-hand rule.

FAQs on Vector Operations

What are Vector Operations?

Vector operations are mathematical operations performed on vector quantities, including addition, subtraction, dot product, and cross product.

What is the Triangle Law of Vector Addition?

This law states that if two vectors are represented by two sides of a triangle, the third side represents their sum.

What is the Parallelogram Law of Vector Addition?

This law states that if two vectors represent adjacent sides of a parallelogram, the diagonal represents their sum.

What is the Cross Product of Two Vectors?

The cross product is a vector operation that results in a vector quantity, perpendicular to the plane formed by the two original vectors.

What is the Dot Product of Two Vectors?

The dot product is a scalar operation that results in a single number, representing the magnitude of one vector in the direction of another.

Vector Operations in PyTorch

Creating a Vector

You can create a vector in PyTorch using the following syntax:

import torch

# Create a vector
A = torch.tensor([7058, 7059, 7060, 7061, 7062])
print(A)
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Arithmetic Operations

You can perform various arithmetic operations on vectors. Here’s a simple example:

# Create two vectors
A = torch.tensor([58, 59, 60, 61, 62])
B = torch.tensor([100, 120, 140, 160, 180])

# Vector operations
print("Addition:", A + B)
print("Subtraction:", A - B)
print("Multiplication:", A * B)
print("Division:", A / B)
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Dot Product

To calculate the dot product of two vectors, use the torch.dot() function:

A = torch.tensor([58, 59, 60, 61, 62])
B = torch.tensor([8, 9, 6, 1, 2])

# Dot product
print("Dot Product:", torch.dot(A, B))
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Linspace Function

You can create evenly spaced values within a specified range using torch.linspace():

# Generate linear values
x = torch.linspace(1, 12)
print(x)
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Plotting Functions

You can visualize functions using PyTorch with libraries like Matplotlib. Here’s an example of plotting a sine function:

import numpy as np
import matplotlib.pyplot as plt

# Create lin space from 1 to 12
x = torch.linspace(1, 12)
y = torch.sin(x)

# Plot
plt.plot(x.numpy(), y.numpy())
plt.title("Sine Function")
plt.show()
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Conclusion

Vector algebra is a fundamental aspect of mathematics with applications across various fields. Understanding vector operations such as addition, subtraction, and multiplication is crucial for tackling complex problems in physics, engineering, and computer science. With tools like PyTorch, these operations become efficient and intuitive, empowering further exploration in data science and machine learning.

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