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Hyperbolic functions occur in the calculations of angles and distances in hyperbolic geometry. They also occur in the solutions of many linear differential equations (such as the equation defining a catenary ), cubic equations, and Laplace's equation in Cartesian coordinates. Laplace's equations are important in many areas of physics, including ...
Newton's law of cooling. In the study of heat transfer, Newton's law of cooling is a physical law which states that the rate of heat loss of a body is directly proportional to the difference in the temperatures between the body and its environment. The law is frequently qualified to include the condition that the temperature difference is small ...
In these equations, g 0, M and R * are each single-valued constants, while P, L, T, and h are multivalued constants in accordance with the table below. The values used for M , g 0 , and R * are in accordance with the U.S. Standard Atmosphere , 1976, and the value for R * in particular does not agree with standard values for this constant. [2]
Arrhenius equation. In physical chemistry, the Arrhenius equation is a formula for the temperature dependence of reaction rates. The equation was proposed by Svante Arrhenius in 1889, based on the work of Dutch chemist Jacobus Henricus van 't Hoff who had noted in 1884 that the van 't Hoff equation for the temperature dependence of equilibrium ...
Half-life (symbol t½) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive. The term is also used more generally to characterize any type of exponential (or, rarely ...
Half time (physics) Half time is the time taken by a quantity to reach one half of its extremal value, where the rate of change is proportional to the difference between the present value and the extremal value (i.e. in exponential decay processes). It is synonymous with half-life, but used in slightly different contexts.
The exponential of X, denoted by eX or exp (X), is the n×n matrix given by the power series. where is defined to be the identity matrix with the same dimensions as . [1] The series always converges, so the exponential of X is well-defined. Equivalently, where I is the n×n identity matrix. When X is an n×n diagonal matrix then exp (X) will be ...
Logistic function. A logistic function or logistic curve is a common S-shaped curve ( sigmoid curve) with the equation. where. is the carrying capacity, the supremum of the values of the function; is the logistic growth rate, the steepness of the curve; and. is the value of the function's midpoint. [1]