Question

Find the domain of 3y/y+5

Answer 1

Set the denominator in
3
y
y
+
5
3
y
y
+
5
equal to
0
0
to find where the expression is undefined.
y
+
5
=
0
y
+
5
=
0
Subtract
5
5
from both sides of the equation.
y
=
−
5
y
=
-
5
The domain is all values of
y
y
that make the expression defined.
Interval Notation:
(
−
∞
,
−
5
)
∪
(
−
5
,
∞
)
(
-
∞
,
-
5
)
∪
(
-
5
,
∞
)
Set-Builder Notation:
{
y
|
y
≠
−
5
}