For which of the following functions is f (a + b) = f (b) + f (a) for all positive numbers a and b?
A. f (x) = x^2
B. f (x) = x + 1
C. f (x) = sqroot x
D. f (x) = 2/x
E. f (x) = -3 x
OA E
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f (a + b) = f (b) + f (a)
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Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
This might not make sense.
f(a+b) = f(a) + f(b) is the definition of a linear function.
Therefore the answers can only be B or E.
f(a) + f(b) = a + b + 2 != f(a+b)
So the answer is E.
Obviously you could go through each of them with values for a and b or variables and multiply out squareds and roots.
f(a+b) = f(a) + f(b) is the definition of a linear function.
Therefore the answers can only be B or E.
f(a) + f(b) = a + b + 2 != f(a+b)
So the answer is E.
Obviously you could go through each of them with values for a and b or variables and multiply out squareds and roots.
