Exponential, trigonometric and hyperbolic trigonometric functions #
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This file contains the definitions of the real and complex exponential, sine, cosine, tangent, hyperbolic sine, hyperbolic cosine, and hyperbolic tangent functions.
The Cauchy sequence consisting of partial sums of the Taylor series of the complex exponential function
The complex exponential function, defined via its Taylor series
Equations
- complex.exp z = (complex.exp' z).lim
The complex sine function, defined via exp
Equations
- complex.sin z = (complex.exp (-z * complex.I) - complex.exp (z * complex.I)) * complex.I / 2
The complex cosine function, defined via exp
Equations
- complex.cos z = (complex.exp (z * complex.I) + complex.exp (-z * complex.I)) / 2
The complex tangent function, defined as sin z / cos z
Equations
- complex.tan z = complex.sin z / complex.cos z
The complex hyperbolic sine function, defined via exp
Equations
- complex.sinh z = (complex.exp z - complex.exp (-z)) / 2
The complex hyperbolic cosine function, defined via exp
Equations
- complex.cosh z = (complex.exp z + complex.exp (-z)) / 2
The complex hyperbolic tangent function, defined as sinh z / cosh z
Equations
- complex.tanh z = complex.sinh z / complex.cosh z
De Moivre's formula
This is an intermediate result that is later replaced by real.add_one_le_exp
; use that lemma
instead.
A finite initial segment of the exponential series, followed by an arbitrary tail.
For fixed n
this is just a linear map wrt r
, and each map is a simple linear function
of the previous (see exp_near_succ
), with exp_near n x r ⟶ exp x
as n ⟶ ∞
,
for any r
.