Question

f(x)=ax2+bx+3a+b关于Y轴对称定义域为[a-1,2a](a.b属于R),f(x)的值域为

Answer 1

关于y轴对称,=>a-1+2a=0,=>a=1/3.

=>b=0.

f(x)=1/3x^2+1

值域是[1.31/27]