bookshelf/Bookshelf/Fraleigh/Chapter_1.lean

24 lines
440 B
Plaintext
Raw Blame History

This file contains ambiguous Unicode characters!

This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.

import Mathlib.Data.Complex.Basic
/-! # Fraleign.Chapter1
Introduction and Examples
-/
namespace Fraleign.Chapter1
open Complex
open HPow
/-! ## Exercises 1 Through 9
In Exercises 1 through 9 compute the given arithmetic expression and give the
answer in the form `a + bi` for `a, b ∈ `.
-/
theorem exercise1 : I^3 = 0 + (-1) * I := calc
I^3
= I * (I * hPow I 1) := rfl
_ = 0 + (-1) * I := by simp
end Fraleign.Chapter1