Math questions part4?

Question

domains of the following?

√x² - 4

3√2x^2 - 8

4√4 - x^2

5√7x3 - 9

All #'s before √ are above the tiny line.. I have no idea what that means in a square root.

Answer 1

the #'s before the / are above the tiny line and it means to take the root of that power

for example 3/27 means to take the cube root of 27 which is 3 because 3*3*3 = 27

1. /x^2 - 4 : the domain is all x greater than or equal to 2 because 2^2 - 4 = 0 and you cannot take the square root if a negative number (at least not yet, you will learn how to in higher math courses)

2. 3/2x^2 - 8 : the domain is all x greater than or equal to 2 because 2* 2^2 - 8 = 0

i think that you should do the rest by yourself because if i give you all of the answers you will not learn

but the trick is to find the number that will make the equation =  0 and the domain is all values higher than that