/kwɒ,drætɪk ɪ'kweɪʒn; kwɑd`rætɪkɪ`kweʒən/
(algebra 代数) equation that uses the square (and no higher power) of an unknown quantity, egx2 + 2x
8 =
0 二次方程式（如x2 + 2x
8 = 0）.

/kwɒ,drætɪk ɪ'kweɪʒn; kwɑd`rætɪkɪ`kweʒən/
(algebra 代数) equation that uses the square (and no higher power) of an unknown quantity, eg x^2 + 2x -
8 =
0 二次方程式（如 x^2 + 2x -
8 = 0）.

n[C]
[Date: 1600-1700; Origin: quadratic from quadrate 'square' (14-21 centuries), from Latin quadratus, past participle of quadrare 'to make square']
technical an equation such ax²+by+c = z, which includes numbers or quantities multiplied by themselves