a → x y = - b ±√b2 - 4xc/2x b → x y = - x ±√x2 - 4ac/2a c → x y = - b ±√b2 - 4ax/2a T.theodor 2022.7.23

f(y) = f(x) ay2 + by + c = dx2 + ex + f T.theodor 2022.7.23

Cartesian coordinate system x：y = 1：1 x：y = α：β T.theodor 2022.7.23

y = y' = ±1 T.theodor 2022.7.23