https://changzh.me/en/tags/tangents/Recent content in Tangents on Blog of BrianHugoenSun, 04 Oct 2026 17:24:00 +0800https://changzh.me/en/posts/conic-tangent-substitution/Sun, 04 Oct 2026 17:24:00 +0800https://changzh.me/en/posts/conic-tangent-substitution/Derive tangent equations for ellipses, hyperbolas, parabolas, and general quadratic curves by preserving the value at the point of contact and scaling every differential equally.