You can put this solution on YOUR website!
For example: I have 4* the square root of -8 when i put it in the calculator it comes up 11.313j but the back of the book says 8j* square root of 2. If i put that into the calculator i get the same answer as i was getting before. 11.313j. I don't know how to get the answer in the back of the book.
The answer in the back of your book is the "exact" answer.
Whereas, the answer you calculated is the approximate "decimal" equivalent.
Thus, your problem:
can be factored as:
we can extract the -1 under the radical and get:
finally, we can pull out a "pair" of the 2's to get: