Vector Magnitude and Direction
A vector has magnitude (length) and direction. Compute |v| = √(x²+y²+z²), unit vector v̂ = v/|v|, and direction angle θ = arctan(y/x) for 2D.
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î=(1,0,0), ĵ=(0,1,0), k̂=(0,0,1) are standard basis vectors. Compare squared magnitudes to avoid square roots. Zero vector (0,0,0) has undefined direction.
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Why: Vectors represent force, velocity, acceleration — quantities with both size and direction.
How: Magnitude is the length: |v| = √(x²+y²+z²). Unit vector has magnitude 1: v̂ = v/|v|. In 2D, direction angle θ = arctan(y/x).
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Enter Vector Components
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🧮 Fascinating Math Facts
Vectors represent force, velocity, acceleration.
— Physics
3D positions, normals, and velocities are all vectors.
— Graphics
Key Takeaways
- • A vector has both magnitude and direction; it is represented by components or .
- • The magnitude is — the length of the vector.
- • The unit vector has magnitude 1 and points in the same direction.
- • In 2D, the direction angle from the positive x-axis is .
- • The zero vector (0, 0, 0) has magnitude 0; its direction and unit vector are undefined.
Did You Know?
Vectors represent force, velocity, acceleration — quantities with both size and direction.
3D positions, normals, and velocities are all vectors. Unit vectors are used for lighting.
GPS uses 3D vectors to represent your position and velocity relative to Earth.
Feature vectors in ML are n-dimensional; magnitude and direction matter for similarity.
Structural forces and moments are vector quantities analyzed by component and magnitude.
î = (1,0,0), ĵ = (0,1,0), k̂ = (0,0,1) are the standard basis vectors in 3D.
Understanding Vectors
A vector in 2D or 3D space is defined by its components. The magnitude (length) is:
The unit vector (direction only) is:
Expert Tips
Avoid Square Roots
When comparing magnitudes, compare squared magnitudes: if |v|² < |w|² then |v| < |w|.
Normalization
Always check |v| > 0 before computing the unit vector to avoid division by zero.
2D vs 3D
For 2D vectors, use z=0. The direction angle is only defined in 2D.
Component Form
Component form (x, y, z) is equivalent to xî + yĵ + zk̂ in standard basis.
Frequently Asked Questions
What is a vector?
A vector is a quantity with both magnitude (length) and direction. It is represented by components (x, y) in 2D or (x, y, z) in 3D.
How do I find the magnitude?
Use |v| = √(x² + y² + z²). For 2D, set z=0 so |v| = √(x² + y²).
What is a unit vector?
A unit vector has magnitude 1. Compute it by dividing the vector by its magnitude: v̂ = v/|v|.
When is the direction angle defined?
Only for 2D vectors. It is the angle from the positive x-axis: θ = arctan(y/x).
What about the zero vector?
The zero vector (0,0,0) has magnitude 0. Its direction and unit vector are undefined.
Can I use negative components?
Yes. Negative components point in the opposite direction along that axis.
What is component form?
Component form is the ordered tuple (x, y, z) that specifies the vector's projection onto each axis.
How to Use This Calculator
- Enter the vector components (x, y) for 2D or (x, y, z) for 3D. Toggle "3D mode" if needed.
- Click "Calculate" to compute magnitude, unit vector, direction angle (2D), and component form.
- Review the results in the gradient card and metrics grid.
- Check the visualization to see the vector in 3D space.
- Copy results for homework or reports.
Disclaimer: This calculator uses standard floating-point arithmetic. For the zero vector, unit vector and direction angle are undefined. Results are suitable for educational and professional use.
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