Correct Answer [spoiler](E)[/spoiler]
(a) f(x)=x^2
f(a+b) = (a+b)²
f(a)= a²
f(b)= b²
(a+b)² = a² + b²? NO
(b) f(x)=x+1
f(a+b) = (a+b+1)
f(a) = a+1
f(b) = b+1
(a+b+1)= a+1 + b+1? NO
(c) f(x)=sqrt(x)
f(a+b) = sqrt(a+b)
f(a) = sqrt(a)
f(b) = sqrt(b)
sqrt(a+b) = sqrt(a) + sqrt(b)? NO
(d) f(x)=2/x
f(a+b) = 2/(a+b)
f(a) = (2/a)
f(b) = (2/b)
2/(a+b) = (2/a) + (2/b) ? NO
(e) f(x)=-3x
f(a+b) = -3(a+b) = -3a - 3b
f(a) = -3a
f(b) = -3b
-3a - 3b = -3a -3b? YES
Do you have to do all this? No, I would have started by option (b) or (e) 'cause they are more likely to be the correct answer.
Last edited by
MAAJ on Thu Mar 31, 2011 12:38 pm, edited 1 time in total.
"There's a difference between interest and commitment. When you're interested in doing something, you do it only when circumstance permit. When you're committed to something, you accept no excuses, only results."
