find the domain of the function: f(x)= 2x

Question

anonymous · Answer

domain is all real numbers because you can multiply any number by 2

anonymous · Answer

how would i write that out? like if i was working it out?

amistre64 · Answer

in general, the domain is the set of numbers that does NOT make the function go bad

anonymous · Answer

first of all the domain is supposed to be part of the definition of the function, but in this case the question really is "what is the largest set of numbers for which you can evaluate the function".  in general you have to worry about two things: you cannot divide by 0 and you cannot take the square root of a negative number

anonymous · Answer

so if you see a polynomial like 
$$f(x)=2x$$ or
$$g(x)=x^2-x$$ just say "all real numbers'

anonymous · Answer

if you see 
$$f(x)=\frac{1}{x-1}$$ you would say "all real numbers except 1"

anonymous · Answer

and if you see 
$$f(x)=\sqrt{x+2}$$ you would say 
$$x\geq -2$$

anonymous · Answer

I just need to know how to work out f(x)=2x because i dont't understand it