Imaginary numbers: -9-16 both under the square root

[nickilin]

-9-16 both under the square root. My instructor doesn't go over new material very well, so I don't know even how to do these.
Thanks :?:

 

[Deleted member 4993]

go to:

http://www.purplemath.com/modules/complex.htm

for a quick review.

Also read your text book - specially the example problems.

To begin - first step:

-9 - 16 = ??[without the square root]

 

[stapel]

-9-16 both under the square root.

Does the above mean either of the following?

. . . . .sqrt[-9 - 16]

. . . . .sqrt[-9] sqrt[-16]

Or something else? Also, what were the instructions? :?:

My instructor doesn't go over new material very well, so I don't know even how to do these.

Ah. So you need links to lessons, so you can learn enough to attempt your homework. :idea:

Fortunately, there are loads of great lessons available online! :wink:

. . . . .Google results for "imaginary square negative simplify"

Have fun!

Eliz.

 

[nickilin]

I did got to this link, and we have a new book this year that is almost as useless as our teacher. The answer in out book is 5i for this problem, but given the rules we went over it doesn't make sense. The answer that I got is -3i-4i

 

[nickilin]

sqrt-9-16
Does that make more sense?

I have been looking a lot at the links on purple math.

 

[Deleted member 4993]

I did got to this link, and we have a new book this year that is almost as useless as our teacher. The answer in out book is 5i for this problem, but given the rules we went over it doesn't make sense. The answer that I got is -3i-4i

I think you have been asked to find

\(\displaystyle sqrt{-9-16}\)


first you need to find:

-9 - 16 = ? [without the square root]

then take square root

 

[Mrspi]

-9 - 16 = -9 + (-16)

Evaluate that first.....

Then take the square root. It's an "order of operations" thing.

 

[nickilin]

THANK YOU!!!