# Thread: Just need this clarified please.

1. ## Just need this clarified please.

Hello,
In my book it shows x=10(sqrt(1+4^4)-1)

I am not sure about the -1 trying to figure out the velocity derivative.
so its 10((1+4^4)^1/2-1)
Is this how it will be written?? never seen it with a -1 at the end after a square root.
So for the derivative it's
5(1-4^4)^-1/2 -1????
Is this correct. just wanting to see if I have it correct before proceeding further.
Thanks
Joanne

2. Originally Posted by bradycat
Hello,
In my book it shows x=10(sqrt(1+4^4)-1)

I am not sure about the -1 trying to figure out the velocity derivative.
so its 10((1+4^4)^1/2-1)
Is this how it will be written?? never seen it with a -1 at the end after a square root.
So for the derivative it's
5(1-4^4)^-1/2 -1????
Is this correct. just wanting to see if I have it correct before proceeding further.
Thanks
Joanne
If you take the derivative of a constant, you get 0 and 10(sqrt(1+4^4)-1) is just a number.

Can you type out the problem you were given verbatim?