For which of the following functions is f(a+b) = f(a) + f(b) for all positive numbers a and b?
The answer is -3x. Could anybody show me how to get to the answer.
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ornelaspedro
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dumb.doofus
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Bouncer.. didnt get it.. dont you need to define what is F(x) .. what is given is just one property of F(x)..ornelaspedro wrote:For which of the following functions is f(a+b) = f(a) + f(b) for all positive numbers a and b?
The answer is -3x. Could anybody show me how to get to the answer.
I feel something is missing here..
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ornelaspedro
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I know !!! It makes no sense to me either. I got this question on the gmatprep practice test one. That's all the information you are given. Anyways, if you can think of something I would really appreciate it.
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dumb.doofus
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aaaaaaaaaaaah.... got it..
it's pretty simple.. if I am thinking correctly
well, just put the values..
let's say f(x) = -3x
so f(a+b) = -3(a+b) = -3a -3b --- (1)
and f(a) + f(b) = -3a - 3b --- (2)
(1) = (2)
so f(x) = -3x suffices f(a+b) = f(a) + f(b)
HTH
it's pretty simple.. if I am thinking correctly
well, just put the values..
let's say f(x) = -3x
so f(a+b) = -3(a+b) = -3a -3b --- (1)
and f(a) + f(b) = -3a - 3b --- (2)
(1) = (2)
so f(x) = -3x suffices f(a+b) = f(a) + f(b)
HTH
One love, one blood, one life. You got to do what you should.
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Uri
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are u sure that u have copied the entire problem?ornelaspedro wrote:For which of the following functions is f(a+b) = f(a) + f(b) for all positive numbers a and b?
The answer is -3x. Could anybody show me how to get to the answer.
