SOLUTION: I am working on expressing negative square roots in terms of j. 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
Question 418197: I am working on expressing negative square roots in terms of j. 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. Answer by nerdybill(7384) (Show Source):
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.
.
realize that:
.
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:
