(x^2)/9+(y^2)/9 =1

解答

\frac{x ^{2}}{9} + \frac{y ^{2}}{9} = 1

(a, b) = (0, 0), r = 3

求解步骤

\frac{x ^{2}}{9} + \frac{y ^{2}}{9} = 1

将

\frac{x ^{2}}{9} + \frac{y ^{2}}{9} = 1

改写为圆标准方程

(x - 0)^{2} + (y - 0)^{2} = 3^{2}

因此圆的性质是:

(a, b) = (0, 0), r = 3

x = y^{2} - 1

\frac{( x - 3 ) ^{2}}{81} - \frac{( y + 5 ) ^{2}}{144} = 1

x = \frac{1}{4} y^{2}

x^{2} + y^{2} - 4 y = 0

x^{2} = - 8 y