Question

find the domain of the rational function
f(y)=y+8
y^2-8y

Answer 1

So domain in this case is all of the things that y can't equal.
Since the denominator can never be zero, just simplify y^2-8y =/= 0 until you get your answer.
y^2-8y =/= 0
y^2 =/= 8y
Divide y from both sides
y =/= 8

Also y can't equal zero, as 0^2-8(0)=0

So your answer is y =/= 8,0