20 points for this question:
Find the domain.

Answer:
The Domain D = {y ∈ R / y ≠ [tex]\dfrac{b}{2}[/tex] y ≠ 0}
Step-by-step explanation:
Let ,
f(y) = [tex]\dfrac{b^{2} - 4by }{2y^{2} - by }[/tex] - [tex]\dfrac{4y}{b-2y}[/tex]
The above function would be defined only when the denominator of anyone or both the terms of the function do not become 0 -
[tex]2y^{2} - by[/tex] ≠ 0 and b - 2y ≠ 0
∴ y(2y - b) ≠ 0 and y ≠[tex]\dfrac{b}{2}[/tex]
Either y ≠ 0 or y ≠ [tex]\dfrac{b}{2}[/tex]
∵ The domain of a function consists of only those points where the function is defined -
The Domain D consists of all y ∈ Real numbers such that y ≠ 0 and y ≠ [tex]\dfrac{b}{2}[/tex]