二次曲线
quadric curves
Quadratic curve
Quadric curve
quadratic curves
secondary curve
quadratic equation
conic curve
the second-order curve
quafric curve
second degree curve
curve of second order
curve of second degree
conic
conic section
conies
conical section
conic sections
Conics
二次曲线逼近法
Second curve near way
Secon d curve near way