What is the range of the function #f(x)=(x-3)/(x+4)#?

1 Answer
Apr 23, 2017

Answer:

#y inRR,y!=1#

Explanation:

To find the value/s that y cannot be.

#"Rearrange to make x the subject"#

#y=(x-3)/(x+4)#

#color(blue)"cross-multiplying ""gives"#

#y(x+4)=x-3#

#rArrxy+4y=x-3#

#rArrxy-x=-3-4y#

#rArrx(y-1)=-3-4y#

#rArrx=(-3-4y)/(y-1)#

The denominator cannot be zero. Equating the denominator to zero and solving gives the value that y cannot be.

#"solve " y-1=0rArry=1larrcolor(red)" excluded value"#

#"range is " y inRR,y!=1#