对称轴为a/2f(x)=x2-ax+3的对称轴在[－2,2]时2>=a/2>=-24>=a>=-4f(x)=【x2-ax+3】min=f(a/2)=3-a^2/2>=aa>=-1+2根号2或小于等于-1-2根号2a属于【-4,-1-2根号2】并【-1+2根号2,4】f(x)=x2-ax+3的对称轴在[2,正无穷]时...