# Thread: Those pesky square roots

1. ## Those pesky square roots

1)

I type this in my calculator but I get domain error and I put in N, but it was wrong.

2)
I think it's |z| ? I'm not sure...

3)
Would this be $x^4$

2. Originally Posted by fluffy_penguin
1)

I type this in my calculator but I get domain error and I put in N, but it was wrong.

2)
I think it's |z| ? I'm not sure...

3)
Would this be $x^4$
1) is it 4?
3) i think you're right..

3. 1. How did you get 4? I get domain error. > >
2. Ok ty.

I'd feel better if you were sure I was right for 3.

4. Originally Posted by fluffy_penguin
1. How did you get 4? I get domain error. > >
2. Ok ty.

I'd feel better if you were sure I was right for 3.
-4 is a constant number and if it is raised to an even power, it will become positive.. hence, if you take an even root, it is always defined.. i think, check out how you typed it on you gadget.. Ü
for number three, by definition,

$\sqrt{x^8} = \sqrt{({x^4})^2} = |x^4|$

but x^4 is always positive, hence you can write it simply x^4

5. Thanks. ^ ^

6. Number 1 could be $\pm 4$, but assuming you are taking principal roots the answer would be $4$