Public Domain Source http://commons.wikimedia.org/wiki/File:Parabola_in_projective_space.svg 圖表 gnuplot 寓言 射影空間中的抛物線
Education and school vector footage of different books and objects. Images of schoolbooks and dictionaries with letters on the covers, algebra textbook, stationery items, magnifying glass, academic cap and diploma tied with a ribbon. Free vectors for studying and education designs 功能區 已 教育 教育圖形
A parabola on a Cartesian coordinate grid. Typeface is Tuffy (public domain, created by Thatcher Ulrich) from openfontlibrary.org 代數 cartesian coordinates conic section 比喻
