ax²+(3a-2)x+5=a[x+(3/2)-(1/a)]²+5-[(3/2)-(1/a)]²≥0 → a≥0 且 5-[(3/2)-(1/a)]²≥0 →
→ a≥0,11a²+12a-4≥0；
解不等式可得 a