求值域!y=x^2-3x+5 x∈(-3,1)

问题描述:

求值域!y=x^2-3x+5 x∈(-3,1)

y=x^2-3x+5=x^2-2*3/2*x+(3/2)^2-(3/2)^2+5=(x-3/2)^2-9/4+5 =(x-3/2)^2+11/4 x∈(-3,1)即-3