4X²-4X+M=0有两个实数根,
则:16-16m≥0,
m≤1,
(1).若M为正整数,
m≤1,所以m=1
此方程为:4x^2-4x+1=0
x1=x2=1/2
(2)设此方程的两个实数根为a、b,
a+b=4,ab=m/4
4b^-4b+m=0
2b^2-2b=-m/2
y=ab-2b²+2b+1
=ab-(2b^2-2b)+1
=m/4-(-m/2)+1
=(3m/4)+1
因为m≤1
所以 y≤3/4+1=7/4
y的范围 y≤7/4.
4X²-4X+M=0有两个实数根,
则:16-16m≥0,
m≤1,
(1).若M为正整数,
m≤1,所以m=1
此方程为:4x^2-4x+1=0
x1=x2=1/2
(2)设此方程的两个实数根为a、b,
a+b=4,ab=m/4
4b^-4b+m=0
2b^2-2b=-m/2
y=ab-2b²+2b+1
=ab-(2b^2-2b)+1
=m/4-(-m/2)+1
=(3m/4)+1
因为m≤1
所以 y≤3/4+1=7/4
y的范围 y≤7/4.