Math Help Forum: Domain range

Find the largest possible domain for the following funtions:

a) sqrt x(x-4)

b) sqrt 2x(x-4)

Thank you in advance for your help

Originally Posted by Oasis1993

Find the largest possible domain for the following funtions:

a) sqrt x(x-4)

b) sqrt 2x(x-4)

Thank you in advance for your help

Obviously, you can't have a negative sign under the square root.

So only values of such that is positive will be in the domain of .

Spoiler:

has two zeroes at and , so any value of will yield a negative value. Thus your domain is .

Part (b) is identical.