How do you find the domain and range for f(x)= (x+2)/(x+7)f(x)=x+2x+7?

1 Answer
Nov 4, 2017

The domain is x in RR-{-7}. The range is y in RR-{1}

Explanation:

The function is f(x)=(x+2)/(x+7)

The denominator must be !=0

Therefore,

x+7!=0, =>, x!=-7

The domain is x in RR-{-7}

Let y=(x+2)/(x+7)

y(x+7)=x+2

xy+7y=x+2

xy-x=2-7y

x(y-1)=2-7y

x=(2-7y)/(y-1)

The denominator is !=0

y-1!=0, =>, y!=1

The range is y in RR-{1}

graph{(x+3)/(x+7) [-32.99, 24.74, -14.6, 14.27]}