若方程 ax^2+2hxy+by^2+2gx+2fg'+c=0 ①表示圆心为 (x_1,y_0) ,半径为r的圆,它的方程是 (x-x_0)^2+(y-y_0)^2=r2②,将②式展开与①比较,可得 a=b≠0 ,b=0, g^2+f^2-ac=a^2r^20 .反之,若 a=b≠0 , g^2+f^2-ac0 ,则方程①化为x^2+y^2+(2g)/ax+(2f)...
( ). 2 A.y=(x+2) 2 -3 B.y=(x+2) 2 -2 C.y=(x-2) 2 -3 D.y=(x-2) 2 -2 能力升级 8.二次函数y=a(x+k) 2 +k(a≠0),无论k 取什么实数,图象顶点必在( ). A.直线y=-x 上 B.x 轴上 C.直线y=x 上 D.y 轴上 9.(1) 抛物线y=3x 2 -2x 可由抛物线y=3x 2 ...
[PATCH] ipq8074: add YUNCORE AX880 BDF This patch add yuncore ax880 from stock fw (bdwlan.b290). This bdf file was generated with ath11k-bdencoder stock fw bdf and board-2.json ``` [ { "board": [ { "names": [ "bus=ahb,qmi-chip-id=0,qmi-board-id=255,variant=Yuncore-AX880...
【解析】若方程 ax^2+2hxy+by^2+2gx+2fg'+c=0 ①表示圆心为 (x_1,y_0) ,半径为r的圆,它的方程是 (x-x_0)^2+(y-y_0)^2=r^2= ,将② 式展开与①比较,可得 a=b≠0 ,b=0, g^2+f^2-ac=a^2r^20 .反之,若 a=b≠q0 , g^2+f^2-ac0 ,则方程①化为x^2+y^2+(...