The output voltage has a shape that approximates a square waveform. Simpson's rule approximates the integrand by a piecewise quadratic function. Most global mean radii are based on the reference ellipsoid, which approximates the geoid. The Earth's orbit approximates an ellipse. Hence, the forward difference divided by approximates the derivative when is small. The system as a whole approximates a (constant-ratio) exponential curve. The resulting value approximates from above the original value. For this example, the exponential distribution approximates the distribution of failure times. The heated filament emits light that approximates a continuous spectrum. Formulae are available for molecules whose shape approximates to that of a symmetric top. Minority group data also approximates national averages. In short, linearization approximates the output of a function near formula 2. An alternate description is that a neural net approximates the language function. From there Interstate 86 to Pocatello roughly approximates the trail. This series approximates with arbitrary precision, provided the number of summands is large enough.