Function Strategy:Question 21:Page92:Equalities

[ashishparmar01]

This question is from the 3rd edition of GMAT Strategy guide: Equalities, Inequalities and VICs: 3rd edition
Q21: For which of the following functions does f(x) = f(2-x)?
A) f(x) = x + 2
B) f(x) = 2x - x^2
C) f(x) = 2 - x
D) f(x) = (2 - x)^2
E) f(x) = x^2

The answer given is B, which is correct even by my calculations. But, I think, I see a flaw in the solution given in the book. By picking 4 as a number, for f(4) the solution is
2(4) - 4^2 = -8

But for f(2-4), the solution given is (2 - 4) - (2 - 4)^2 = -2-4 = -6

The two solutions do not equate. Instead the solution should have been
2(2 - 4) - (2 - 4)^2 = -4-4=-8

Is this correct or am I missing something?

Thanks
Ashish

[saurav.raaj]

I think the answer is D!

[ashishparmar01]

Can you post your calculation?

[JonathanSchneider]

The answer is indeed B. To the original poster: you are absolutely correct. This is an error we hope to fix in our next printing. Thanks for pointing it out here as well :)

[christiancryan]

Thanks for the catch! Unfortunately, we only recently sent this particular book back to the printer for another print run, having incorporated other revisions, but we've added this fix to the list for the next round of edits. I appreciate your feedback.

Chris Ryan
Director of Instructor & Product Development