How do you find the domain and range of y = 1 / (x+5)?

2 Answers
Apr 4, 2017

Domain is {x in RR ; x != -5 }
Range is {y in RR ; y != 0 }

Explanation:

Domain: Denominator should not be 0 :. x+5 != 0 or x != -5
Domain is any real value except x = -5 or {x in RR ; x != -5 }

Range is any real value except y = 0 or {y in RR ; y != 0 } graph{1/(x+5) [-10, 10, -5, 5]}

Apr 4, 2017

see explanation.

Explanation:

The denominator of y cannot be zero as this would make y undefined. Equating the denominator to zero and solving gives the value that x cannot be.

"solve " x+5=0rArrx=-5

rArr"domain is " x in RR,x!=-5

"Rearrange "y " to make x the subject"

y(x+5)=1

rArrxy+5y=1rArrxy=1-5y

rArrx=(1-5y)/y

Applying the same reasoning as for the domain we obtain.

"range is " y in RR,y!=0