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Unit vector

From Simple English Wikipedia, the free encyclopedia

A unit vector is any vector that is one unit in length. Unit vectors are often notated the same way as normal vectors, but with a mark called a circumflex over the letter (e.g. 𝐯̂ is the unit vector of 𝐯.)[1][2]

To make a vector into a unit vector, one just needs to divide it by its length: 𝐯̂=𝐯/‖𝐯‖.[3] The resulting unit vector will be in the same direction as the original vector.[4]

Standard basis vectors

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Three common unit vectors are 𝐢̂, 𝐣̂ and 𝐤̂, referring to the three-dimensional unit vectors for the x-, y- and z-axes, respectively. These vectors are called the standard basis vectors of a 3-dimensional Cartesian coordinate system. They are commonly just notated as i, j and k.

They can be written as follows: 𝐢̂=[100],𝐣̂=[010],𝐤̂=[001]

For the i-th standard basis vector of a vector space, the symbol ei (or êi) may be used.[4] This refers to the vector with 1 in the i-th component, and 0 elsewhere.

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References

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  1. ↑ "Comprehensive List of Algebra Symbols". Math Vault. 2020-03-25. Retrieved 2020-08-19.
  2. ↑ "Unit Vector". www.mathsisfun.com. Retrieved 2020-08-19.
  3. ↑ Weisstein, Eric W. "Unit Vector". mathworld.wolfram.com. Retrieved 2020-08-19.
  4. 1 2 "Unit Vectors | Brilliant Math & Science Wiki". brilliant.org. Retrieved 2020-08-19.