Dot Product vs. Cross Product: Know the Difference
By Shumaila Saeed || Updated on December 25, 2023
Dot Product computes the scalar product of two vectors, emphasizing direction alignment, while Cross Product finds their vector product, reflecting their perpendicular relationship.
Key Differences
Dot Product measures the extent to which two vectors are parallel, calculating the product of their magnitudes and the cosine of the angle between them. Cross Product, conversely, finds a vector perpendicular to both, reflecting their mutual orientation, with a magnitude equal to the area of the parallelogram formed by them.
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Dec 12, 2023
While Dot Product results in a scalar value, representing the projection of one vector onto another, Cross Product yields a vector, indicative of the space spanned by the original vectors. The direction of the Cross Product vector is determined by the right-hand rule, unlike the Dot Product which doesn't involve directionality in its result.
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Dec 12, 2023
The Dot Product is commutative, meaning the order of vectors does not alter the result. In contrast, Cross Product is anti-commutative, where swapping vectors reverses the direction of the resulting vector, though the magnitude remains the same.
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Dec 12, 2023
In applications, the Dot Product is often used in physics to calculate work done or in machine learning for similarity measures. The Cross Product finds its use in calculating torques, rotational forces, and in computer graphics for determining the orientation of surfaces.
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Dec 12, 2023
The zero-result scenarios differ: for Dot Product, a zero indicates orthogonality (perpendicularity) of vectors, while for Cross Product, a zero result signifies parallel or anti-parallel vectors.
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Dec 12, 2023
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Comparison Chart
Geometric Interpretation
Cosine of angle between vectors
Area of parallelogram formed by vectors
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Order Sensitivity
Commutative (order doesn't matter)
Anti-commutative (order reverses direction)
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Zero Result Implication
Vectors are perpendicular
Vectors are parallel or anti-parallel
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Dec 12, 2023
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Dot Product and Cross Product Definitions
Dot Product
The product of the magnitudes of two vectors and the cosine of the angle between them.
The dot product of two orthogonal vectors is always zero.
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Dec 05, 2023
Cross Product
A tool for determining the relative orientation of two vectors.
The cross product is used in robotics to compute the orientation of limbs.
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Dec 05, 2023
Dot Product
A scalar representation of vector alignment.
Maximizing the dot product in optimization algorithms finds the best alignment of vectors.
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Dec 05, 2023
Cross Product
A vector perpendicular to two given vectors in three-dimensional space.
The cross product of two vectors defines the normal to the plane they span.
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Dec 05, 2023
Dot Product
A metric for similarity in multidimensional space.
In data analysis, the dot product of two data vectors reveals their directional similarity.
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Dec 05, 2023
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Cross Product
A means of finding a vector orthogonal to two given vectors.
In 3D modeling, the cross product is used to determine surface normals for rendering.
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Dec 05, 2023
Dot Product
A mathematical operation yielding the sum of the products of corresponding entries in two sequences of numbers.
In machine learning, the dot product of weight and feature vectors determines the activation of a neuron.
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Cross Product
A non-commutative operation on two vectors yielding a third vector.
The cross product's direction can be determined using the right-hand rule.
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Dec 05, 2023
Dot Product
A measure of the projection of one vector onto another.
In physics, the dot product calculates the work done by a force along a displacement.
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Dec 05, 2023
Cross Product
The vector product with a magnitude equal to the area of the parallelogram that the vectors span.
In physics, the cross product helps calculate the torque exerted by a force.
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Dec 05, 2023
Repeatedly Asked Queries
What is the Dot Product?
A scalar value representing the product of the magnitudes of two vectors and the cosine of the angle between them.
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Dec 12, 2023
Can Dot Product be negative?
Yes, if the angle between vectors is more than 90 degrees, the Dot Product is negative.
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Dec 12, 2023
What does a zero Cross Product indicate?
It indicates that the vectors are parallel or anti-parallel.
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Dec 12, 2023
When is the Dot Product zero?
When the vectors are orthogonal (perpendicular) to each other.
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Dec 12, 2023
How is the Cross Product different from the Dot Product?
The Cross Product yields a vector perpendicular to the original vectors, unlike the scalar result of the Dot Product.
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Dec 12, 2023
Can we use the Dot Product for non-orthogonal vectors?
Yes, it measures their degree of alignment irrespective of orthogonality.
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Dec 12, 2023
How is the Cross Product used in physics?
In calculating torques and rotational forces.
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Dec 12, 2023
Is the Cross Product applicable in 2D space?
No, it's defined only in 3D space.
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Dec 12, 2023
What does the magnitude of the Cross Product represent?
The area of the parallelogram formed by the two vectors.
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Dec 12, 2023
What's the significance of the direction of the Cross Product?
It shows the right-hand rule orientation relative to the original vectors.
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Dec 12, 2023
How do we calculate the Dot Product?
By multiplying the magnitudes of the vectors and the cosine of the angle between them.
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Dec 12, 2023
Can Dot and Cross Products be used interchangeably?
No, they serve different mathematical and geometrical purposes.
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Dec 12, 2023
Can the Dot Product be used for any number of dimensions?
Yes, it's applicable in any dimensional space.
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Dec 12, 2023
What role does the Cross Product play in computer graphics?
In determining the orientation of surfaces for rendering.
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Dec 12, 2023
What does a large Dot Product indicate?
It suggests that vectors are closely aligned.
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Dec 12, 2023
What applications use the Dot Product?
Physics (work calculation), machine learning (similarity measures), and more.
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Dec 12, 2023
What is the significance of a negative Cross Product?
The Cross Product itself is a vector, its direction indicates the relative orientation of the original vectors.
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Dec 12, 2023
How is the direction of the Cross Product determined?
Using the right-hand rule, based on the order of the vectors.
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Dec 12, 2023
Does the Cross Product always result in a vector perpendicular to both vectors?
Yes, that's the defining characteristic of the Cross Product.
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Dec 12, 2023
Is the Dot Product commutative?
Yes, the order of vectors doesn't change the result.
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Dec 12, 2023
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About Author
Written by
Shumaila SaeedShumaila Saeed, an expert content creator with 6 years of experience, specializes in distilling complex topics into easily digestible comparisons, shining a light on the nuances that both inform and educate readers with clarity and accuracy.