& lt3> Opening direction: lower symmetry axis: x =-1; Vertex coordinates:-1, 1.
& lt3> Opening direction: lower symmetry axis: X=2 Vertex coordinates: ﹙ 2,0 ﹚.
& lt4> Opening direction: upper symmetry axis: X = 4；; Vertex coordinates:-5-.4
Supplement:
& lt 1 & gt； Opening direction: upper symmetry axis: x = ﹣ 1/3 vertex coordinates: ﹙ 1/3, ﹣ 1/3.
& lt2> Opening direction: lower symmetry axis: x =-1; Vertex coordinates:-1, 1.
& lt3> Opening direction: lower symmetry axis: X=2 Vertex coordinates: ﹙ 2,0 ﹚.
& lt4> Opening direction: upper symmetry axis: X = 4；; Vertex coordinates:-5-.4