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Exercise 4

Avg difficulty 2.5

Suppose that v=3w\vvec=3\wvec.

  1. What is the relationship between v⋅v\vvec\cdot\vvec and w⋅w\wvec\cdot\wvec?

  2. What is the relationship between ∣v∣\len{\vvec} and ∣w∣\len{\wvec}?

  3. If v=sw\vvec=s\wvec for some scalar ss, what is the relationship between v⋅v\vvec\cdot\vvec and w⋅w\wvec\cdot\wvec? What is the relationship between ∣v∣\len{\vvec} and ∣w∣\len{\wvec}?

  4. Suppose that v=[3−22]\vvec=\threevec{3}{-2}2. Find a scalar ss so that svs\vvec has length 1.

Austin, Understanding Linear Algebra, §6.1 The dot product, Exercise 4

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Adapted from Understanding Linear Algebra © 2023 David Austin. Licensed under CC BY 4.0. Source: Understanding Linear Algebra. Imported at revision 3e6dced.