function problem from prep software...

[poonamchiK]

f (a+b) = f(a) + f(b)

[editor: DO NOT abbreviate problems. if another problem is posted like this -- without the salient text of the question prompt -- it will be deleted immediately. thanks.]

a. f(x) = lxl
b. f(x) = x+1
c. f(x) = sq.root x
d. f(x) = 2/x
e. f(x) = -3x

i thought it was b bt thats wrong!

[ps63739]

f(a) = a+1
f(b) = b+1
f(a)+f(b) = a+b+2

and f(a+b) = (a+b) + 1

Now that proves that f(a+b)!= f(a)+f(b)

[akhp77]

f (a+b) = f(a) + f(b)

e. f(x) = -3x

f(a+b) = -3(a+b) = -3a -3b = f(a) + f(b)

[RonPurewal]

this problem is solved here:
for-which-of-the-following-functions-is-f-a-b-f-a-f-b-t2795.html