1、由已知焦点坐标可知,半焦距c=2;
已知点(2/5,-2/3)到两焦点的距离和为 2a=√[(-2-2/5)²+(2/3)²]+√[(2-2/5)²+(2/3)²]=(4√86+26)/15;
∴ a=(2√86+13)/15,则 b²=a²-c²=(52√86-33)/225;
椭圆标准方程为:x²/[(867+52√86)/225]+y²/[(52√86-33)/225]=1;
2、P:5x²-4x-1≥0,即(5x+1)(x-1)≥0,x≤-1/5或x>1;非P:-1/5
1、由已知焦点坐标可知,半焦距c=2;
已知点(2/5,-2/3)到两焦点的距离和为 2a=√[(-2-2/5)²+(2/3)²]+√[(2-2/5)²+(2/3)²]=(4√86+26)/15;
∴ a=(2√86+13)/15,则 b²=a²-c²=(52√86-33)/225;
椭圆标准方程为:x²/[(867+52√86)/225]+y²/[(52√86-33)/225]=1;
2、P:5x²-4x-1≥0,即(5x+1)(x-1)≥0,x≤-1/5或x>1;非P:-1/5