x^2+3x+y^2+8x=25

解答

x^{2} + 3 x + y^{2} + 8 x = 25

(a, b) = (- \frac{11}{2}, 0), r = \frac{221}{2}

求解步骤

x^{2} + 3 x + y^{2} + 8 x = 25

将

x^{2} + 3 x + y^{2} + 8 x = 25

改写为圆标准方程

(x - (- \frac{11}{2}))^{2} + (y - 0)^{2} = (\frac{221}{2})^{2}

因此圆的性质是:

(a, b) = (- \frac{11}{2}, 0), r = \frac{221}{2}

x^{2} + 4 x = 10 - y^{2}

x^{2} + y^{2} = 6 x + 6 y

ce n t er x^{2} + y^{2} = 25

ce n t er x^{2} + y^{2} - 5 x + 4 y = 46

ce n t er x^{2} + y^{2} - 2 x + 4 y - 4 = 0