How do I find the domain of the function #f(x) = 2x#? Precalculus Functions Defined and Notation Domain 1 Answer Bill Jorgensen Jun 20, 2018 #{x|x in RR}# Explanation: #f(x) = 2x# is just a line, all lines have a domain of all real numbers. #{x|x in RR}# graph{2x [-10, 10, -5, 5]} 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)=5x^2+2x-1#? How do I find the domain of the square root function? See all questions in Domain Impact of this question 13387 views around the world You can reuse this answer Creative Commons License