Trigonometric and hyperbolic trigonometric functions #
This file contains the definitions of the sine, cosine, tangent, hyperbolic sine, hyperbolic cosine, and hyperbolic tangent functions.
The complex sine function, defined via exp
Equations
- Complex.sin z = (Complex.exp (-z * Complex.I) - Complex.exp (z * Complex.I)) * Complex.I / 2
Instances For
The complex cosine function, defined via exp
Equations
- Complex.cos z = (Complex.exp (z * Complex.I) + Complex.exp (-z * Complex.I)) / 2
Instances For
The complex tangent function, defined as sin z / cos z
Equations
- Complex.tan z = Complex.sin z / Complex.cos z
Instances For
The complex cotangent function, defined as cos z / sin z
Equations
- z.cot = Complex.cos z / Complex.sin z
Instances For
The complex hyperbolic sine function, defined via exp
Equations
- Complex.sinh z = (Complex.exp z - Complex.exp (-z)) / 2
Instances For
The complex hyperbolic cosine function, defined via exp
Equations
- Complex.cosh z = (Complex.exp z + Complex.exp (-z)) / 2
Instances For
The complex hyperbolic tangent function, defined as sinh z / cosh z
Equations
- Complex.tanh z = Complex.sinh z / Complex.cosh z
Instances For
theorem
Complex.sinh_add
(x y : ℂ)
:
Complex.sinh (x + y) = Complex.sinh x * Complex.cosh y + Complex.cosh x * Complex.sinh y
theorem
Complex.cosh_add
(x y : ℂ)
:
Complex.cosh (x + y) = Complex.cosh x * Complex.cosh y + Complex.sinh x * Complex.sinh y
theorem
Complex.sinh_sub
(x y : ℂ)
:
Complex.sinh (x - y) = Complex.sinh x * Complex.cosh y - Complex.cosh x * Complex.sinh y
theorem
Complex.cosh_sub
(x y : ℂ)
:
Complex.cosh (x - y) = Complex.cosh x * Complex.cosh y - Complex.sinh x * Complex.sinh y
theorem
Complex.sinh_conj
(x : ℂ)
:
Complex.sinh ((starRingEnd ℂ) x) = (starRingEnd ℂ) (Complex.sinh x)
@[simp]
theorem
Complex.cosh_conj
(x : ℂ)
:
Complex.cosh ((starRingEnd ℂ) x) = (starRingEnd ℂ) (Complex.cosh x)
theorem
Complex.tanh_conj
(x : ℂ)
:
Complex.tanh ((starRingEnd ℂ) x) = (starRingEnd ℂ) (Complex.tanh x)
@[simp]
@[simp]
@[simp]
@[simp]
@[simp]
@[simp]
theorem
Complex.cosh_two_mul
(x : ℂ)
:
Complex.cosh (2 * x) = Complex.cosh x ^ 2 + Complex.sinh x ^ 2
theorem
Complex.cosh_three_mul
(x : ℂ)
:
Complex.cosh (3 * x) = 4 * Complex.cosh x ^ 3 - 3 * Complex.cosh x
theorem
Complex.sinh_three_mul
(x : ℂ)
:
Complex.sinh (3 * x) = 4 * Complex.sinh x ^ 3 + 3 * Complex.sinh x
theorem
Complex.two_sin
(x : ℂ)
:
2 * Complex.sin x = (Complex.exp (-x * Complex.I) - Complex.exp (x * Complex.I)) * Complex.I
theorem
Complex.two_cos
(x : ℂ)
:
2 * Complex.cos x = Complex.exp (x * Complex.I) + Complex.exp (-x * Complex.I)
theorem
Complex.sin_add
(x y : ℂ)
:
Complex.sin (x + y) = Complex.sin x * Complex.cos y + Complex.cos x * Complex.sin y
theorem
Complex.cos_add
(x y : ℂ)
:
Complex.cos (x + y) = Complex.cos x * Complex.cos y - Complex.sin x * Complex.sin y
theorem
Complex.sin_sub
(x y : ℂ)
:
Complex.sin (x - y) = Complex.sin x * Complex.cos y - Complex.cos x * Complex.sin y
theorem
Complex.cos_sub
(x y : ℂ)
:
Complex.cos (x - y) = Complex.cos x * Complex.cos y + Complex.sin x * Complex.sin y
theorem
Complex.sin_add_mul_I
(x y : ℂ)
:
Complex.sin (x + y * Complex.I) = Complex.sin x * Complex.cosh y + Complex.cos x * Complex.sinh y * Complex.I
theorem
Complex.sin_eq
(z : ℂ)
:
Complex.sin z = Complex.sin ↑z.re * Complex.cosh ↑z.im + Complex.cos ↑z.re * Complex.sinh ↑z.im * Complex.I
theorem
Complex.cos_add_mul_I
(x y : ℂ)
:
Complex.cos (x + y * Complex.I) = Complex.cos x * Complex.cosh y - Complex.sin x * Complex.sinh y * Complex.I
theorem
Complex.cos_eq
(z : ℂ)
:
Complex.cos z = Complex.cos ↑z.re * Complex.cosh ↑z.im - Complex.sin ↑z.re * Complex.sinh ↑z.im * Complex.I
theorem
Complex.sin_sub_sin
(x y : ℂ)
:
Complex.sin x - Complex.sin y = 2 * Complex.sin ((x - y) / 2) * Complex.cos ((x + y) / 2)
theorem
Complex.cos_sub_cos
(x y : ℂ)
:
Complex.cos x - Complex.cos y = -2 * Complex.sin ((x + y) / 2) * Complex.sin ((x - y) / 2)
theorem
Complex.sin_add_sin
(x y : ℂ)
:
Complex.sin x + Complex.sin y = 2 * Complex.sin ((x + y) / 2) * Complex.cos ((x - y) / 2)
theorem
Complex.cos_add_cos
(x y : ℂ)
:
Complex.cos x + Complex.cos y = 2 * Complex.cos ((x + y) / 2) * Complex.cos ((x - y) / 2)
theorem
Complex.tan_mul_cos
{x : ℂ}
(hx : Complex.cos x ≠ 0)
:
Complex.tan x * Complex.cos x = Complex.sin x
theorem
Complex.cos_add_sin_I
(x : ℂ)
:
Complex.cos x + Complex.sin x * Complex.I = Complex.exp (x * Complex.I)
theorem
Complex.cos_sub_sin_I
(x : ℂ)
:
Complex.cos x - Complex.sin x * Complex.I = Complex.exp (-x * Complex.I)
theorem
Complex.inv_one_add_tan_sq
{x : ℂ}
(hx : Complex.cos x ≠ 0)
:
(1 + Complex.tan x ^ 2)⁻¹ = Complex.cos x ^ 2
theorem
Complex.tan_sq_div_one_add_tan_sq
{x : ℂ}
(hx : Complex.cos x ≠ 0)
:
Complex.tan x ^ 2 / (1 + Complex.tan x ^ 2) = Complex.sin x ^ 2
theorem
Complex.cos_three_mul
(x : ℂ)
:
Complex.cos (3 * x) = 4 * Complex.cos x ^ 3 - 3 * Complex.cos x
theorem
Complex.sin_three_mul
(x : ℂ)
:
Complex.sin (3 * x) = 3 * Complex.sin x - 4 * Complex.sin x ^ 3
theorem
Complex.exp_mul_I
(x : ℂ)
:
Complex.exp (x * Complex.I) = Complex.cos x + Complex.sin x * Complex.I
theorem
Complex.exp_add_mul_I
(x y : ℂ)
:
Complex.exp (x + y * Complex.I) = Complex.exp x * (Complex.cos y + Complex.sin y * Complex.I)
theorem
Complex.exp_eq_exp_re_mul_sin_add_cos
(x : ℂ)
:
Complex.exp x = Complex.exp ↑x.re * (Complex.cos ↑x.im + Complex.sin ↑x.im * Complex.I)
@[simp]
@[simp]
theorem
Complex.cos_add_sin_mul_I_pow
(n : ℕ)
(z : ℂ)
:
(Complex.cos z + Complex.sin z * Complex.I) ^ n = Complex.cos (↑n * z) + Complex.sin (↑n * z) * Complex.I
De Moivre's formula
Extension for the positivity
tactic: Real.cosh
is always positive.
Instances For
@[simp]
theorem
Complex.abs_cos_add_sin_mul_I
(x : ℝ)
:
Complex.abs (Complex.cos ↑x + Complex.sin ↑x * Complex.I) = 1
@[simp]
theorem
Complex.abs_exp_eq_iff_re_eq
{x y : ℂ}
:
Complex.abs (Complex.exp x) = Complex.abs (Complex.exp y) ↔ x.re = y.re