ANSWER
(-∞,+∞)
Step-by-step explanation
The given polynomial function is:
![f(x)=10x^3 +18x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/v5e5913n7u9auttqe5nhz9cgxhbrd9obxg.png)
The domain refers to all values of x that make the function defined.
Polynomial functions are defined for all real values of x
The domain is the set of all real numbers.
This is written in symbolic representation as
(-∞,+∞)