y=(7x-3)/(4x+2)的值域

题目

y=(7x-3)/(4x+2)的值域

答案

y=(7x-3)/(4x+2)
=[(7/4)(4x+2)-13/2]/(4x+2)
=7/4- (13/2)/(4x+2)
∵ 4x+2≠0
∴ y=7/4- (13/2)/(4x+2)≠7/4
即函数y=(7x-3)/(4x+2)的值域{y|y≠7/4}