# How to | Take a Derivative

*Mathematica* makes it easy to take even the most complicated derivatives involving any of its huge range of differentiable special functions.

Define a function with one variable, :

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To find , type and press Shift+Enter:

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This method works for any order; just add more primes:

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Or use D. Its first argument is the function and its second argument is the variable:

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For higher-order derivatives using D, the second argument is a list, :

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Define a function with two variables, :

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Take the first derivative with respect to and the second with respect to by combining the two forms (single variable and list):

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The Heaviside theta function is treated as if it had an infinite pulse at zero, where it is undefined:

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The HeavisideTheta function has special derivative properties:

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This plots the HeavisideTheta (green) and DiracDelta (red) functions:

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