What is the domain and range of y = (x + 2) /( x + 5)?

1 Answer
Jun 18, 2018

The domain is x in (-oo,-5) uu(-5,+oo). The range is y in (-oo,1)uu(1,+oo)

Explanation:

The denominator must be !=0

Therefore,

x+5!=0

=>, x!=-5

The domain is x in (-oo,-5) uu(-5,+oo)

To find the range, proceed as follows :

y=(x+2)/(x+5)

=>, y(x+5)=x+2

=>, yx+5y=x+2

=>, yx-x=2-5y

=>, x(y-1)=2-5y

=>, x=(2-5y)/(y-1)

The denominator must be !=0

Therefore,

y-1!=0

=>, y!=1

The range is y in (-oo,1)uu(1,+oo)

graph{(x+2)/(x+5) [-26.77, 13.77, -10.63, 9.65]}