How do you find the domain of the radical function?

Question

f(x) = - square root(7-x)

Answer 1

The radicand 7 - x must be nonnegative, so the domain is:
7 - x >= 0, or x <= 7

Alternatively, you can write the domain in interval notation: (-infinity, 7]

Answer 2

the number inside of the square root can never be negative. The smallest number you can have inside is 0. After that you always have to go up. Therefore, to get 0, x = 7. For the inside value to get bigger, x has to get smaller. Thus, the domain of this equation is x <= (less than or equal to) 7.

Answer 3

domain equals x less then or equal to 7.