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mehravikas
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x^2+y^2=1...(Given)
This statement can be written as (x+y)^2-2xy=1...(1)
statement 1:
Applying xy=0 in (1) we get
(x+y)^2=1
x+y=1 or x+y = -1
So this statement is insufficient
statement 2:
y=0
We have no information about x
Insufficient
Combining both the statements we have
x+y=1 or x+y=-1 and y=0
which gives rise to two values of x (i.e 1,-1) and y=1
so x+y will be 1 or -1
Hence the ans is E...Hope this helps
