URL:https://s3-us-west-2.amazonaws.com/courses-images-archive-read-only/wp-content/uploads/sites/924/2015/11/25201303/CNX_Precalc_Figure_03_02_0112.jpg
掲載元:https://courses.lumenlearning.com/odessa-collegealgebra/chapter/determine-a-quadratic-functions-minimum-or-maximum-value/