设a是整数,0≤b≤1,若a2=2b(a+b),则b值为______
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∵a2=2b(a+b),
∴2a2=4ab+4b2,
∴3a2=a2+4ab+4b2=(a+2b)2,
∴±
a=a+2b
即b=
a或b=
a
又∵0≤b≤1,a是整数,
当0≤
a≤1时,0≤a≤
+1
∴a=0,此时b=0,满足条件;
a=1,此时b=
,满足条件;
a=2,此时b=
?1,满足条件;
当0≤
∴2a2=4ab+4b2,
∴3a2=a2+4ab+4b2=(a+2b)2,
∴±
3 |
即b=
?1+
| ||
2 |
?1?
| ||
2 |
又∵0≤b≤1,a是整数,
当0≤
?1+
| ||
2 |
3 |
∴a=0,此时b=0,满足条件;
a=1,此时b=
| ||
2 |
a=2,此时b=
3 |
当0≤
?1?
|