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poonam1279
- Master | Next Rank: 500 Posts
- Posts: 145
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This can be solved by simply checking with all answer choices,=.
a) f(x)= x^2
f(a+b)=(a+b)^2=a^2+b^2+2ab
f(a)+f(b) = a^2+b^2
So, a is not the answer
b) f(x) = x+1
f(a+b)=a+b+1
f(a)+f(b) = a+1+b+1 = a+b+2
So, b is not the answer
c) f(x)= root(x)
Since root(a+b) <> root(a) + root(b)
So, c is not the answer
d) 2/(a+b) <> 2/a + 2/b
So, d is not the answer
e) -3(a+b) = -3a-3b
This will be equal for all values of a and b
Hence E is the answer.
