Positive part

In mathematics, the positive part of a real or extended real-valued function is defined by the formula

Intuitively, the graph of ${\displaystyle f^{+}}$ is obtained by taking the graph of ${\displaystyle f}$, chopping off the part under the x-axis, and letting ${\displaystyle f^{+}}$ take the value zero there.

Similarly, the negative part of f is defined as

Note that both f⁺ and f⁻ are non-negative functions. A peculiarity of terminology is that the 'negative part' is neither negative nor a part (like the imaginary part of a complex number is neither imaginary nor a part).

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