2a的平方+a+1= 2(a+1/4)^2+7/8>0
3a的平方-2a+1=3(a-1/3)^2+2/3>0
f(x)在R上是偶函数,在区间[负无穷大,0]上递增
f(x)在在区间[0,+∞)上递减
f(2a的平方+a+1)3a^2-2a+1
a^2-3a
2a的平方+a+1= 2(a+1/4)^2+7/8>0
3a的平方-2a+1=3(a-1/3)^2+2/3>0
f(x)在R上是偶函数,在区间[负无穷大,0]上递增
f(x)在在区间[0,+∞)上递减
f(2a的平方+a+1)3a^2-2a+1
a^2-3a