Module: Mathlib.Analysis.Real.Pi.Irrational

Goal state before:
pp: case convert_2.convert_2
θ : ℝ
n : ℕ
f : ℝ → ℝ := fun x ↦ 1 - x ^ 2
u₁ : ℝ → ℝ := fun x ↦ f x ^ (n + 1)
u₁' : ℝ → ℝ := fun x ↦ -(2 * (↑n + 1) * x * f x ^ n)
v₁ : ℝ → ℝ := fun x ↦ sin (x * θ)
v₁' : ℝ → ℝ := fun x ↦ cos (x * θ) * θ
u₂ : ℝ → ℝ := fun x ↦ x * f x ^ n
u₂' : ℝ → ℝ := fun x ↦ f x ^ n - 2 * ↑n * x ^ 2 * f x ^ (n - 1)
v₂ : ℝ → ℝ := fun x ↦ cos (x * θ)
v₂' : ℝ → ℝ := fun x ↦ -sin (x * θ) * θ
hfd : Continuous f
hu₁d : Continuous u₁'
hv₁d : Continuous v₁'
hu₂d : Continuous u₂'
hv₂d : Continuous v₂'
hu₁_eval_one : u₁ 1 = 0
hu₁_eval_neg_one : u₁ (-1) = 0
t : u₂ 1 * v₂ 1 - u₂ (-1) * v₂ (-1) = 2 * (0 ^ n * cos θ)
hf : ∀ (x : ℝ), HasDerivAt f (-2 * x) x
hu₁ : ∀ (x : ℝ), HasDerivAt u₁ (u₁' x) x
hv₁ : ∀ (x : ℝ), HasDerivAt v₁ (v₁' x) x
hu₂ : ∀ (x : ℝ), HasDerivAt u₂ (u₂' x) x
hv₂ : ∀ (x : ℝ), HasDerivAt v₂ (v₂' x) x
this✝ : ∀ (x : ℝ), u₂' x = (2 * ↑n + 1) * f x ^ n - 2 * ↑n * f x ^ (n - 1)
this : Continuous v₂
⊢ -(2 * 2 * ((↑n + 1) * (0 ^ n * cos θ))) +
      2 * (↑n + 1) * ∫ (x : ℝ) in -1..1, (2 * ↑n + 1) * (f x ^ n * v₂ x) - 2 * ↑n * (f x ^ (n - 1) * v₂ x) =
    -(2 * 2 * ((↑n + 1) * (0 ^ n * cos θ))) + 2 * (↑n + 1) * (2 * ↑n + 1) * I n θ - 4 * (↑n + 1) * ↑n * I (n - 1) θ

Tactic:
integral_sub,

Goal state after:
case convert_2.convert_2
θ : ℝ
n : ℕ
f : ℝ → ℝ := fun x ↦ 1 - x ^ 2
u₁ : ℝ → ℝ := fun x ↦ f x ^ (n + 1)
u₁' : ℝ → ℝ := fun x ↦ -(2 * (↑n + 1) * x * f x ^ n)
v₁ : ℝ → ℝ := fun x ↦ sin (x * θ)
v₁' : ℝ → ℝ := fun x ↦ cos (x * θ) * θ
u₂ : ℝ → ℝ := fun x ↦ x * f x ^ n
u₂' : ℝ → ℝ := fun x ↦ f x ^ n - 2 * ↑n * x ^ 2 * f x ^ (n - 1)
v₂ : ℝ → ℝ := fun x ↦ cos (x * θ)
v₂' : ℝ → ℝ := fun x ↦ -sin (x * θ) * θ
hfd : Continuous f
hu₁d : Continuous u₁'
hv₁d : Continuous v₁'
hu₂d : Continuous u₂'
hv₂d : Continuous v₂'
hu₁_eval_one : u₁ 1 = 0
hu₁_eval_neg_one : u₁ (-1) = 0
t : u₂ 1 * v₂ 1 - u₂ (-1) * v₂ (-1) = 2 * (0 ^ n * cos θ)
hf : ∀ (x : ℝ), HasDerivAt f (-2 * x) x
hu₁ : ∀ (x : ℝ), HasDerivAt u₁ (u₁' x) x
hv₁ : ∀ (x : ℝ), HasDerivAt v₁ (v₁' x) x
hu₂ : ∀ (x : ℝ), HasDerivAt u₂ (u₂' x) x
hv₂ : ∀ (x : ℝ), HasDerivAt v₂ (v₂' x) x
this✝ : ∀ (x : ℝ), u₂' x = (2 * ↑n + 1) * f x ^ n - 2 * ↑n * f x ^ (n - 1)
this : Continuous v₂
⊢ -(2 * 2 * ((↑n + 1) * (0 ^ n * cos θ))) +
      2 * (↑n + 1) *
        ((∫ (x : ℝ) in -1..1, (2 * ↑n + 1) * (f x ^ n * v₂ x)) - ∫ (x : ℝ) in -1..1, 2 * ↑n * (f x ^ (n - 1) * v₂ x)) =
    -(2 * 2 * ((↑n + 1) * (0 ^ n * cos θ))) + 2 * (↑n + 1) * (2 * ↑n + 1) * I n θ - 4 * (↑n + 1) * ↑n * I (n - 1) θ

case convert_2.convert_2.hf
θ : ℝ
n : ℕ
f : ℝ → ℝ := fun x ↦ 1 - x ^ 2
u₁ : ℝ → ℝ := fun x ↦ f x ^ (n + 1)
u₁' : ℝ → ℝ := fun x ↦ -(2 * (↑n + 1) * x * f x ^ n)
v₁ : ℝ → ℝ := fun x ↦ sin (x * θ)
v₁' : ℝ → ℝ := fun x ↦ cos (x * θ) * θ
u₂ : ℝ → ℝ := fun x ↦ x * f x ^ n
u₂' : ℝ → ℝ := fun x ↦ f x ^ n - 2 * ↑n * x ^ 2 * f x ^ (n - 1)
v₂ : ℝ → ℝ := fun x ↦ cos (x * θ)
v₂' : ℝ → ℝ := fun x ↦ -sin (x * θ) * θ
hfd : Continuous f
hu₁d : Continuous u₁'
hv₁d : Continuous v₁'
hu₂d : Continuous u₂'
hv₂d : Continuous v₂'
hu₁_eval_one : u₁ 1 = 0
hu₁_eval_neg_one : u₁ (-1) = 0
t : u₂ 1 * v₂ 1 - u₂ (-1) * v₂ (-1) = 2 * (0 ^ n * cos θ)
hf : ∀ (x : ℝ), HasDerivAt f (-2 * x) x
hu₁ : ∀ (x : ℝ), HasDerivAt u₁ (u₁' x) x
hv₁ : ∀ (x : ℝ), HasDerivAt v₁ (v₁' x) x
hu₂ : ∀ (x : ℝ), HasDerivAt u₂ (u₂' x) x
hv₂ : ∀ (x : ℝ), HasDerivAt v₂ (v₂' x) x
this✝ : ∀ (x : ℝ), u₂' x = (2 * ↑n + 1) * f x ^ n - 2 * ↑n * f x ^ (n - 1)
this : Continuous v₂
⊢ IntervalIntegrable (fun x ↦ (2 * ↑n + 1) * (f x ^ n * v₂ x)) volume (-1) 1

case convert_2.convert_2.hg
θ : ℝ
n : ℕ
f : ℝ → ℝ := fun x ↦ 1 - x ^ 2
u₁ : ℝ → ℝ := fun x ↦ f x ^ (n + 1)
u₁' : ℝ → ℝ := fun x ↦ -(2 * (↑n + 1) * x * f x ^ n)
v₁ : ℝ → ℝ := fun x ↦ sin (x * θ)
v₁' : ℝ → ℝ := fun x ↦ cos (x * θ) * θ
u₂ : ℝ → ℝ := fun x ↦ x * f x ^ n
u₂' : ℝ → ℝ := fun x ↦ f x ^ n - 2 * ↑n * x ^ 2 * f x ^ (n - 1)
v₂ : ℝ → ℝ := fun x ↦ cos (x * θ)
v₂' : ℝ → ℝ := fun x ↦ -sin (x * θ) * θ
hfd : Continuous f
hu₁d : Continuous u₁'
hv₁d : Continuous v₁'
hu₂d : Continuous u₂'
hv₂d : Continuous v₂'
hu₁_eval_one : u₁ 1 = 0
hu₁_eval_neg_one : u₁ (-1) = 0
t : u₂ 1 * v₂ 1 - u₂ (-1) * v₂ (-1) = 2 * (0 ^ n * cos θ)
hf : ∀ (x : ℝ), HasDerivAt f (-2 * x) x
hu₁ : ∀ (x : ℝ), HasDerivAt u₁ (u₁' x) x
hv₁ : ∀ (x : ℝ), HasDerivAt v₁ (v₁' x) x
hu₂ : ∀ (x : ℝ), HasDerivAt u₂ (u₂' x) x
hv₂ : ∀ (x : ℝ), HasDerivAt v₂ (v₂' x) x
this✝ : ∀ (x : ℝ), u₂' x = (2 * ↑n + 1) * f x ^ n - 2 * ↑n * f x ^ (n - 1)
this : Continuous v₂
⊢ IntervalIntegrable (fun x ↦ 2 * ↑n * (f x ^ (n - 1) * v₂ x)) volume (-1) 1