I Absolute value bars in dot product derivation

member 731016 · Mar 20, 2023

Dose someone please know why they have the absolute value bars in this derivation?

many thanks!

jedishrfu · Mar 20, 2023

The absolute value bars indicate the length of the vector not absolute value of a number.

Of course, the vector length is always positive.

I think this convention was more popular in early vector math books where as now they use the double v-bar notation.

https://en.wikipedia.org/wiki/Norm_(mathematics)

member 731016 · Mar 20, 2023

jedishrfu said:

The absolute value bars indicate the length of the vector not absolute value of a number.

Of course, the vector length is always positive.

I think this convention was more popular in early vector math books where as now they use the double v-bar notation.

https://en.wikipedia.org/wiki/Norm_(mathematics)

Thank you for your help @jedishrfu !

I Absolute value bars in dot product derivation

Thread 'The colorful world of ##2\times 2## complex matrices'

Thread 'About the existence of Hamel basis for vector spaces'

Thread 'When are Markov Matrices also Martingales?'

Similar threads

I How to show ##p(x)=g(x)x\pm 1\in\Bbb{Q}[x]## is irreducible in ##\Bbb{Q}_{\Bbb{Z}}[x]##?

I Showing ##k[x_1,\ldots,x_n]/\mathfrak{a}## is finite dimensional

I How do we distinguish two different notations for cokernel and coimage?

I Localising a non integral domain at a prime

I ##(A/\mathfrak{a})_{\mathfrak{p}/\mathfrak{a}}## and its isomorphism?

Insights Thinking Outside The Box Versus Knowing What’s In The Box

Insights Why Entangled Photon-Polarization Qubits Violate Bell’s Inequality

Insights Quantum Entanglement is a Kinematic Fact, not a Dynamical Effect

Insights What Exactly is Dirac’s Delta Function? - Insight

Insights Relativator (Circular Slide-Rule): Simulated with Desmos - Insight

Insights Fixing Things Which Can Go Wrong With Complex Numbers