Quote:
Originally Posted by nomadmba
Here are three questions that have left me scratching my head. I have the answers, but not the methodology:
1. For which of the following functions is f(a+b)= f(a) + f(b) for all positive numbers a and b?
a. f(x) = x*x
b. f(x) = x + 1
c. f(x) = sq. root of x
d. f(x) = 2/x
e. f(x) = -3x
Thanks.
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Its E
Method is replace x by a, b & (a+b)
1. x*x = x
2
a
2 + b
2 = (a+b)
2 - 2ab
not equal to (a+b)
2
2. a+1 + b + 1= (a+b) + 2
not equal to (a+b) + 1
3. root a + root b not equal to root(a+b)
4. 2 / a + 2/b not equal to 2/(a+b)
5. -3a + (- 3b) = -3 (a+b) -- > Correct