求不等式(1-3y)^2+(2y+1)^2>13(y-1)(y+1)
问题描述:
求不等式(1-3y)^2+(2y+1)^2>13(y-1)(y+1)
答
原不等式等价于
1-6y+9y^2+4y^2+4y+1-13(y^2-1)>0
2y+11得y