From 2f7e9eaa7f0794d4e55e501b085de4d67434b497 Mon Sep 17 00:00:00 2001 From: Andrew Lorimer Date: Mon, 11 Feb 2019 22:04:39 +1100 Subject: [PATCH] add index rule for i^n in C --- spec/complex.md | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/spec/complex.md b/spec/complex.md index d0b6625..5809170 100755 --- a/spec/complex.md +++ b/spec/complex.md @@ -53,6 +53,8 @@ Therefore.. - $i^{4n+2} = -1$ - $i^{4n+3} = -i$ +Divide by 4 and take remainder + ### Multiplying complex expressions If $z_1 = a+bi$ and $z_2=c+di$, then @@ -97,7 +99,7 @@ ${z_1 \over z_2} = {{(a+bi)(c-di)} \over {c^2+d^2}}$ To solve $z^2+a^2=0$ (sum of two squares): $z^2+a^2=z^2-(ai)^2$ -              $=(z+ai)(z-ai)$ +              $=(z+ai)(z-ai)$ ## Polar form -- 2.47.1