求值域,(1)y=2x平方+4x-7/(x+1)平方+2 (2)y=5x-1/4x+2
问题描述:
求值域,(1)y=2x平方+4x-7/(x+1)平方+2 (2)y=5x-1/4x+2
答
y=2x平方+4x-7/(x+1)平方+2
=2(x+1)^2-9/(x+1)平方+2
=2- 13/(x+1)平方+2
>=-5/4
y=5x-1/4x+2
x≠-1/2