parabolic cusp

例句：

1. 1. The parabolic curve describes the pathof an object moving along a curve.
   抛物线描述了物体沿着曲线移动的路径。
2. 2.The asymptote of a parabola is its vertical line at infinity.
   抛物线的渐近线是无穷远处的垂直线。
3. 3. The vertexof a triangle is the point wherethe three sides meet.
   三角形的顶点是三条边相交的地方。