TeXipedia

cosh

Represents the hyperbolic cosine function, a fundamental mathematical operation used in hyperbolic geometry and engineering calculations.

Overview

Essential in advanced mathematics and physics applications where hyperbolic functions play a key role.

  • Commonly used in analyzing physical phenomena like catenary curves and electrical signals
  • Appears frequently in differential equations, especially those modeling wave propagation
  • Important in special relativity and electromagnetic theory
  • Often paired with sinh and tanh in mathematical expressions
  • Particularly useful in solving problems involving exponential growth and decay

Examples

Definition of hyperbolic cosine in terms of exponentials.

coshx=ex+ex2\cosh x = \frac{e^x + e^{-x}}{2}
\cosh x = \frac{e^x + e^{-x}}{2}

Solution to a hyperbolic differential equation.

y(x)=Acosh(λx)+Bsinh(λx)y(x) = A\cosh(\lambda x) + B\sinh(\lambda x)
y(x) = A\cosh(\lambda x) + B\sinh(\lambda x)

Identity relating hyperbolic cosine to regular cosine.

cosh(ix)=cos(x)\cosh(ix) = \cos(x)
\cosh(ix) = \cos(x)