Question

let f(x)=sqrt(x(x-1))
whats the domain of f

Answer 1

We can't take the square root of a negative number, so we find the inequality:
x^2-x>=0
X^2>=x
which is true for x<=0 and for x>=1. And that is your domain.

Answer 2

so how do you write it???

Answer 3

D=????

Answer 4

there are several notations you can use, this is one: {x|x<=0 OR x>=1} or x<=0 V x>=1 is another.

Answer 5

@Thomas9
"We can't take the square root of a negative number"

Actually you can, it's just that the sqrt sign as written refers to the non-negative square root.

Good answer though.

Answer 6

i know, this question wouldn't be any fun though if you consider complex numbers right?

Answer 7

x^2-x must be non negative.
so domain is(-\[\infty\],0]and[1,\[\infty\])