Auxiliary lemmas #
theorem
DifferentiableAt.comp_ofReal
{e : ℂ → ℂ}
{z : ℝ}
(hf : DifferentiableAt ℂ e ↑z)
:
DifferentiableAt ℝ (fun (x : ℝ) => e ↑x) z
theorem
Differentiable.comp_ofReal
{e : ℂ → ℂ}
(h : Differentiable ℂ e)
:
Differentiable ℝ fun (x : ℝ) => e ↑x
theorem
DifferentiableAt.ofReal_comp
{z : ℝ}
{f : ℝ → ℝ}
(hf : DifferentiableAt ℝ f z)
:
DifferentiableAt ℝ (fun (y : ℝ) => ↑(f y)) z
theorem
Differentiable.ofReal_comp
{f : ℝ → ℝ}
(hf : Differentiable ℝ f)
:
Differentiable ℝ fun (y : ℝ) => ↑(f y)
theorem
HasDerivAt.of_hasDerivAt_ofReal_comp
{z : ℝ}
{f : ℝ → ℝ}
{u : ℂ}
(hf : HasDerivAt (fun (y : ℝ) => ↑(f y)) u z)
:
∃ (u' : ℝ), u = ↑u' ∧ HasDerivAt f u' z