Rule for converting trig identities into hyperbolic identities
John
There is a simple rule of thumb for converting between (circular) trig identities and hyperbolic trig identities known as Osborn’s rule: stick an h on the end of trig functions and flip signs wherever two sinh functions are multiplied together. Examples For example, the circular identity sin(θ + φ) = sin(θ) cos(φ) + cos(θ) sin(φ) […] The post Rule for converting trig identities into hyperbolic identities first appeared on John D. Cook .