How do I find the domain of the function f(x)=5x^2+2x-1? Precalculus Functions Defined and Notation Domain 1 Answer Massimiliano Apr 17, 2015 A polynomial function has as domain the whole set of RR, so: (-oo,+oo). Answer link Related questions What is the domain of a function? What are common mistakes students make when working with domain? How does the domain of a function relate to its x-values? What is the domain of a linear function? What is the domain of a quadratic function? What is the domain of a function like f(x) = 5x^2? What is the domain of f(x) = {(1, 2), (3, 4), (5, 6), (7, 8), (9, 10), (10, 10)}? What is the domain of f(x) = x? How do I find the domain of the function f(x) = 2x? How do I find the domain of the square root function? See all questions in Domain Impact of this question 4974 views around the world You can reuse this answer Creative Commons License