Question

(1)y=2x+5/x+2 的 值域求法

Answer 1

y=(2x+4+1)/(x+2)

=[2(x+2)+1]/(x+2)

=2(x+2)/(x+2)+1/(x+2)

=2+1/(x+2)

1/(x+2)≠0

所以2+1/(x+2)≠2

所以值域是y≠2