x²+2(1+a)x+(3a²+4ab+4b²+2)=0△=4(1+a)²-4(3a²+4ab+4b²+2)=4a²+8a+4-12a²-16ab-16b²-8=-8a²+8a-4-16ab-16b²≥0∴2a²-2a+1+4ab+4b²≤0(a...