Sum of Squares of Hyperbolic Secant and Tangent/Also presented as

Sum of Squares of Hyperbolic Secant and Tangent: Also known as

Sum of Squares of Hyperbolic Secant and Tangent can also be reported as:

$1 - \tanh^2 x = \sech^2 x$

or:

$1 - \sech^2 x = \tanh^2 x$

Sources

• 1981: Murray R. Spiegel: Theory and Problems of Complex Variables (SI ed.) ... (previous) ... (next): $2$: Functions, Limits and Continuity: The Elementary Functions: $5$
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): hyperbolic function