Exsecant

The exsecant function $\mathrm{exsec}$ is defined by $$\mathrm{exsec}(z)=\sec(z)-1,$$ where $\sec$ denotes the secant.

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  Trig functions diagram using the unit circle.

References

• 1964: Milton Abramowitz and Irene A. Stegun: Handbook of mathematical functions ... (previous) ... (next): $4.3.147$