SOLUTION: My teacher proved that -1 = 1, homework is to find out what is wrong with the proof. I cant do it. Help, thanks Mick.
-1/1=1/-1
....Take the square root of both sides;-
(-
Question 181401: My teacher proved that -1 = 1, homework is to find out what is wrong with the proof. I cant do it. Help, thanks Mick.
-1/1=1/-1
....Take the square root of both sides;-
(-1/1)^.5=(1/-1)^.5
....Take the square root of each term;-
(-1)^.5/(1)^.5=(1)^.5/(-1)^.5
....Sq Root -1 = i Sq Root 1 = 1;-
i/1=1/i
....Cross multiply;-
i^2=1^2
....Sq Root i is -1 and SqRoot 1 is 1;-
-1=1
....QED
Thanks for any help again. Answer by solver91311(24713) (Show Source):
The problem is that you make the claim that which is not exactly true. In fact i is variously defined as or as the root of the equation . In fact, , and not considering both branches is what gets you into absurdity.
