6http://en.wikipedia.org/wiki/Sign_function
see this it might help...
at x=0 signum cant be calculated!!!
signum fn is defined as
sgn x=|x|x
={1 if x>0
{0 if x=0
{-1 if x<0
when x=0 sgn x will become 0/0 which is indeterminate.
so how is its value 0?
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5 Answers
6
30No.. Thats the definition itself.. At zero, the function becomes zero.. Its the definition..
Its not a result on dividing by zero..
Like in modulus function,
we define |x| = -x when x<0
its a definition..
You can define your own function..
1hey ur doubt is exactly true but u can caluculate it for values tending to zero such as 0.0000000000000000001 or -0.0000000000000000000000001 whch is almost 0 for such values and so by default if u draw a graph of such function obviously u can say by default it is zero........
1yar the best way of understanding it (n the one used more than the one u stated) is that any thing +ve output is 1 anything -ve output is -1. for zero its 0.
Moreover as its a compound fn the value at zero has been introduced by the definition,i.e., at zero input it gives an output zero via a direct statement of sgn(0)=0 and not the general definiton it follows
