🌐日本語EnglishEspañolItalianoРусскийالعربية中文日本語EntityQ3980034· pop 5· linked from 81 articles二重尖点thumb|right|214px|A tacnode at the origin of the curve defined by (x^2+y^2-3x)^2 - 4x^2(2-x) = 0.Available in 5 languagesEspañolРусскийItalianoRomanianvia Wikidata sitelinks · CC0Connectionsalgebraic curveEntityRiemann surfaceEntityCategoriesAlgebraic curvesCurvesSingularity theory