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What is a Vector in Maths?

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Types of Vectors with Real-Life Examples

The concept of vector in maths plays a key role in mathematics and is widely applicable to both real-life situations and exam scenarios. Mastering vectors can help you solve problems in geometry, physics, and more advanced subjects.


What Is Vector in Maths?

A vector in maths is defined as a quantity that has both magnitude (size) and direction. Unlike scalar quantities that have only magnitude (like mass or temperature), vectors can be represented as arrows pointing in a certain direction, where the length of the arrow shows their size. You’ll find this concept applied in areas such as physics (force, velocity), engineering (displacement), and computer graphics.


Key Formula for Vector in Maths

Here’s the standard formula to find the magnitude of a vector \( \vec{a} = (x, y) \):
\( |\vec{a}| = \sqrt{x^2 + y^2} \)


Cross-Disciplinary Usage

Vector in maths is not only useful in Maths but also plays an important role in Physics, Computer Science, and daily logical reasoning. Students preparing for exams like JEE, Maths Olympiads, or NEET will see its relevance in many application-based questions, especially when understanding motion, navigation, and forces.


Representation of Vectors

In mathematics, vectors are typically drawn as arrows. The length of the arrow represents its magnitude, and its orientation shows the direction. They can be written as coordinates, like \( \vec{a} = (3, 4) \), or with symbols like \( \vec{v} \). For example, the vector from point A \((1, 2)\) to point B \((4, 6)\) is written as \( \overrightarrow{AB} = (3, 4) \).


Types of Vectors

Type Description Example
Zero Vector A vector with zero magnitude and no direction \( \vec{0} = (0,0) \)
Unit Vector A vector with magnitude 1 \( \hat{i} = (1,0),\, \hat{j} = (0,1) \)
Collinear Vectors Vectors that are parallel to the same line \( (2,4) \) and \( (1,2) \)
Equal Vectors Have same magnitude and direction \( (3,4) \) and \( (3,4) \)

Vector Operations

Addition: To add vectors, sum their corresponding components.
Subtraction: Subtract the components individually.
Multiplying by a scalar: Multiply each component by the scalar value.

  1. Add \( \vec{a} = (2,3) \) and \( \vec{b} = (1,4) \):
    \( \vec{a}+\vec{b}=(2+1, 3+4)=(3,7) \)
  2. Subtract \( \vec{b} \) from \( \vec{a} \):
    \( \vec{a}-\vec{b}=(2-1, 3-4)=(1,-1) \)
  3. Multiply vector \( \vec{a} \) by 3:
    \( 3\vec{a} = (3\times2, 3\times3)=(6,9) \)

Step-by-Step Illustration

  1. Given: \( \vec{a} = (5, 12) \). Find its magnitude.
    1. Write the formula:
    \( |\vec{a}| = \sqrt{5^2 + 12^2} \)

    2. Calculate squares:
    \( 25 + 144 = 169 \)

    3. Square root of 169:
    \( |\vec{a}| = 13 \)

    Final Answer: 13

Speed Trick or Vedic Shortcut

To add two vectors quickly, place the tails together and use the ‘parallelogram rule’ or break each into x and y parts, add them separately, and write the result as a new vector. Many students use these tricks for faster vector addition in exams.


Try These Yourself

  • What is the magnitude of \( \vec{v} = (6,8) \)?
  • Give two real-life examples of vector quantities.
  • Is “speed” a vector? Why or why not?
  • Find the sum of \( (4,5) \) and \( (1,-2) \).

Frequent Errors and Misunderstandings

  • Mixing up scalars (no direction) and vectors (with direction).
  • Forgetting to use both x and y components during calculations.
  • Using the wrong formula for magnitude.
  • Confusing direction with angle.

Relation to Other Concepts

The idea of vector in maths connects closely with scalar and vector quantities and vector addition. Understanding them will help you solve advanced geometry, motion, and force-related problems with ease.


Classroom Tip

A quick way to remember vector in maths: "Length tells you how big, arrow shows you which way!" Vedantu’s teachers often use colorful diagrams to show vectors in class, making the topic clearer for visual learners.


We explored vector in maths—from its definition, formulas, real-life examples, common errors, to its relationship with other concepts. Keep practicing with Vedantu for speedy learning and revision!


FAQs on What is a Vector in Maths?

1. What is a vector in maths?

In mathematics, a vector is a quantity possessing both magnitude (size or length) and direction. Unlike a scalar, which only has magnitude (e.g., temperature, mass), a vector is often represented visually as an arrow. The arrow's length corresponds to the vector's magnitude, and its direction indicates the vector's orientation.

2. How do you represent a vector?

Vectors are commonly represented using boldface letters (e.g., a, b, v) or with an arrow above the letter (e.g., a, b, v). They can also be represented using their components, which are usually given as ordered pairs (in two dimensions) or ordered triples (in three dimensions), like (x, y) or (x, y, z), respectively. Graphically, vectors are illustrated as directed line segments with an arrowhead indicating the direction.

3. What is the difference between scalar and vector?

A scalar is a quantity that has only magnitude (size), while a vector has both magnitude and direction. For example, speed is a scalar (it only tells how fast something is moving), while velocity is a vector (it tells how fast something is moving *and* in what direction). Other examples of scalars are mass, temperature, and energy; examples of vectors are displacement, velocity, acceleration, and force.

4. What are the types of vectors?

There are several types of vectors, including:

  • Zero vector: A vector with zero magnitude.
  • Unit vector: A vector with magnitude 1.
  • Equal vectors: Vectors with the same magnitude and direction.
  • Collinear vectors: Vectors lying on the same line.
  • Coplanar vectors: Vectors lying on the same plane.

5. Where are vectors used in real life?

Vectors are crucial in various fields:

  • Physics: Describing forces, velocity, acceleration, and momentum.
  • Engineering: Analyzing structures and calculating stress, strain, and forces.
  • Computer graphics: Representing positions, movements, and transformations of objects.
  • Navigation: Determining location, speed, and direction.
Essentially, anywhere magnitude and direction are important, vectors play a vital role.

6. How to denote the magnitude of a vector?

The magnitude of a vector a is denoted as |a| or ||a||. It represents the length of the vector. For a vector given by its components (x, y), the magnitude is calculated using the Pythagorean theorem: |a| = √(x² + y²). This extends to three dimensions as |a| = √(x² + y² + z²).

7. How do you add vectors?

Vector addition can be done graphically using the parallelogram law or the head-to-tail method. Analytically, if a = (x₁, y₁) and b = (x₂, y₂), then a + b = (x₁ + x₂, y₁ + y₂). This extends similarly to three dimensions.

8. How do you subtract vectors?

Vector subtraction is similar to addition. To subtract vector b from vector a, we add vector a to the negative of vector b (-b). Analytically, if a = (x₁, y₁) and b = (x₂, y₂), then a - b = (x₁ - x₂, y₁ - y₂).

9. What is a scalar product (dot product) of two vectors?

The scalar product (or dot product) of two vectors a and b results in a scalar value. It is calculated as ab = |a| |b| cos θ, where θ is the angle between the two vectors. It's also calculated as the sum of the products of corresponding components.

10. What is a vector product (cross product) of two vectors?

The vector product (or cross product) of two vectors a and b results in a new vector that is perpendicular to both a and b. Its magnitude is given by |a × b| = |a| |b| sin θ, where θ is the angle between the vectors. The direction is determined using the right-hand rule.

11. What are some common mistakes students make when working with vectors?

Common mistakes include:

  • Confusing scalars and vectors.
  • Incorrectly applying vector addition or subtraction rules.
  • Misunderstanding the concept of magnitude and direction.
  • Errors in calculating dot and cross products.
  • Not paying attention to vector notation and components.