Arithmetic of rates

Euclid wrote that “A ratio is a relation in respect of size between two magnitudes of the same kind.” Magnitudes of different kinds were not considered until Galileo. A ratio between magnitudes a and b is expressed as either a : b or b : a. A quotient is the result of dividing a dividend …

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Two kinds of vector rates

This post builds on the previous one here. Vector rates rates of change are of two kinds. An ordinary rate for the vector change of f relative to a unit of x is defined as: The reciprocal vector rate is the vector reciprocal of an ordinary rate with a vector change of g relative to …

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Two kinds of rates

Rates of change are of two kinds. An ordinary rate for the change of f relative to a unit of x is defined as: The reciprocal rate is the reciprocal of an ordinary rate with a change of g relative to a unit of x is defined as: An ordinary rate has its independent variable …

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From ratios to quotients

Ratios and proportions are symmetric. A:B ≡ B:A and A:B :: C:D iff C:D :: A:B. But when ratios are converted to quotients or fractions, they are no longer symmetric. There must be a convention as to which is the denominator and which is the numerator. In an ordinary fraction or quotient or rate the …

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Speed, pace and inverses

Legend: x-axis coordinate, x; length interval, Δx; independent length interval, x; t-axis coordinate, t; time interval, Δt; independent time interval, t. For scalars: Rates Speed/Pace Symbols Space Time Ordinary (Time) Speed Δx(t)/t measure given Inverse converse Inverse pace (space speed) x/Δt(x) given measure Converse (Space) Pace Δt(x)/x given measure Inverse Inverse speed (time pace) t/Δx(t) …

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Duality of subject and object

This post reflects a previous one here. Color (or colour) is both subjective and objective. Objectively, the rays of color light from a glass prism are different wavelengths (or frequencies) of light. The colors we see are those that reflect from objects; the others are absorbed. Colors are additive. Primary colors are red, green, blue; …

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Instantaneous speed and inverse

This post relates to the previous one here. Speed is the time rate of distance traversed. Pace is the space rate of elapsed time. The (time) speed of a body is the distance traversed per unit of independent time without regard to direction, Δx/t. The instantaneous speed is the speed at a point in space …

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Reciprocal derivative

The reciprocal difference quotient is or The reciprocal derivative of f(x), symbolized by a reversed prime, is the limit of the reciprocal difference quotient as x1 and x2 approach x: or as h approaches zero: The reciprocal derivative of a linear function, f(x) = ax + b, is The reciprocal derivative of a power function, …

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Adding and averaging rates

A rate is the quotient of two quantities with different, but related, units. A unit rate is a rate with a unit quantity, usually the denominator. A vector rate is a rate with a vector quantity, usually the numerator. Rates with the same units may be added, subtracted, and averaged. Addition Rates with the same …

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Reciprocal vector realm

This post expands on Reciprocal Algebra posted here. A vector space, or better a vector realm, to avoid connecting it with physical space, is a set V on which two operations + and · are defined, called vector addition and scalar multiplication. The operation + (vector addition) must satisfy the following conditions: Closure: If u …

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