1.
3x²+2y²=2x ∴3/2x²+y²=x,则y²=x-3/2x².
∴ s=x²+(x-3/2x²)
=-1/2x²+x
=-1/2(x²-2x)
=-1/2(x-1)²+1/2 ∴x=1时,s最大值为1/2.
2.
2x²+y²=4x ∴y²=4x-2x²,
s=x²-(4x-2x²)
=3x²-4x
=3(x²-4/3x)
=3(x-2/3)²-4/3 所以当x=2/3时,s最小值为-4/3.
1.
3x²+2y²=2x ∴3/2x²+y²=x,则y²=x-3/2x².
∴ s=x²+(x-3/2x²)
=-1/2x²+x
=-1/2(x²-2x)
=-1/2(x-1)²+1/2 ∴x=1时,s最大值为1/2.
2.
2x²+y²=4x ∴y²=4x-2x²,
s=x²-(4x-2x²)
=3x²-4x
=3(x²-4/3x)
=3(x-2/3)²-4/3 所以当x=2/3时,s最小值为-4/3.