TheoremBase

The origin is the zero multiple 0x by the pointwise scalar-multiple rules, so linearity of the dot product in its first argument gives 0(x·x)=0.

Proof

The operations and the origin of Rn\mathbb{R}^{n} are the operations of Pointwise Operations on Real-Valued Maps (i) and the constant map 00 of Pointwise Operations on Real-Valued Maps (ii) with I=[n]I=[n], by Euclidean Space Rn\mathbb{R}^n: n-Tuples of Real Numbers with Their Componentwise Operations (iv) and Euclidean Space Rn\mathbb{R}^n: n-Tuples of Real Numbers with Their Componentwise Operations (v). Hence Rules for Pointwise Operations on Real-Valued Maps: a Commutative Ring, Scalar Multiples and Evaluation (iv), with I=[n]I=[n] and f=xf=x, gives 0x=0n0x=0_{n}. The scalar rule of The Dot Product on Rn\mathbb{R}^n Is Symmetric, Bilinear and Positive Definite (ii), applied with xx as the multiplied vector, t=0t=0 and z=xz=x, then gives

0n⋅x=(0x)⋅x=0 (x⋅x).0_{n}\cdot x=(0x)\cdot x=0\,(x\cdot x).

Finally 0 (x⋅x)=00\,(x\cdot x)=0 by Arithmetic and Order Rules in the Real Numbers, Stated for ℝ (vii) (x⋅xx\cdot x being a real number by The Dot Product on Rn\mathbb{R}^n (i)), so 0n⋅x=00_{n}\cdot x=0, which is (i).

Citations

Loading…

Dependencies

Uses0

Loading…

Comments

Log in to comment.

Loading…