In mathematics, the **dot product** or also known as the **scalar product** is an algebraic operation that takes two equal-length sequences of numbers and returns a single number. Let us given two vectors **A** and **B, **and we have to find the dot product of two vectors.

Given that,

and,

Where,

i:the unit vector along the x directions

j:the unit vector along the y directions

k:the unit vector along the z directions

Then the dot product is calculated as:

**Example:**

Given two vectors A and B as,

## Dot Product of Two Vectors in Python

Python provides a very efficient method to calculate the dot product of two vectors. By using **numpy.dot()** method which is available in the NumPy module one can do so.

Syntax:numpy.dot(vector_a, vector_b, out = None)

Parameters:

vector_a:[array_like] if a is complex its complex conjugate is used for the calculation of the dot product.

vector_b:[array_like] if b is complex its complex conjugate is used for the calculation of the dot product.

out:[array, optional] output argument must be C-contiguous, and its dtype must be the dtype that would be returned for dot(a,b).

Return:

Dot Product of vectors a and b. if vector_a and vector_b are 1D, then scalar is returned

**Example 1:**

## Python

`# Python Program illustrating ` `# dot product of two vectors ` ` ` `# Importing numpy module ` `import` `numpy as np ` ` ` `# Taking two scalar values ` `a ` `=` `5` `b ` `=` `7` ` ` `# Calculating dot product using dot() ` `print` `(np.dot(a, b))` |

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**Output:**

35

**Example 2:**

## Python

`# Python Program illustrating ` `# dot product of two vectors ` ` ` `# Importing numpy module ` `import` `numpy as np ` ` ` `# Taking two 1D array ` `a ` `=` `3` `+` `1j` `b ` `=` `7` `+` `6j` ` ` `# Calculating dot product using dot() ` `print` `(np.dot(a, b)) ` |

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**Output:**

(15+25j)

**Example 3:**

## Python

`# Python Program illustrating ` `# dot product of two vectors ` ` ` `# Importing numpy module ` `import` `numpy as np ` ` ` `# Taking two 2D array ` `# For 2-D arrays it is the matrix product ` `a ` `=` `[[` `2` `, ` `1` `], [` `0` `, ` `3` `]] ` `b ` `=` `[[` `1` `, ` `1` `], [` `3` `, ` `2` `]] ` ` ` `# Calculating dot product using dot() ` `print` `(np.dot(a, b))` |

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**Output:**

[[5 4] [9 6]]

**Example 4:**

## Python

`# Python Program illustrating ` `# dot product of two vectors ` ` ` `# Importing numpy module ` `import` `numpy as np ` ` ` `# Taking two 2D array ` `# For 2-D arrays it is the matrix product ` `a ` `=` `[[` `2` `, ` `1` `], [` `0` `, ` `3` `]] ` `b ` `=` `[[` `1` `, ` `1` `], [` `3` `, ` `2` `]] ` ` ` `# Calculating dot product using dot() ` `# Note that here I have taken dot(b, a) ` `# Instead of dot(a, b) and we are going to ` `# get a different ouput for the same vector value ` `print` `(np.dot(b, a))` |

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**Output:**

[[2 4] [6 9]]

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