Hi All,
With inequality-based questions, sometimes the easiest approach is just to come up with a few examples that 'fit' the given prompt and then use those examples to eliminate answer choices.
Here, we're told that 1 - X^2 >= 0. We're asked for ALL of the possible values that fit this inequality.
The 'easiest' value that most Test Takers would immediately 'see' is 1 (since 1 - 1^2 = 0), so X COULD be 1.
Next, since we're dealing with a squared term, -1 would also be a solution (since 1 - [-1]^2 = 0).
So we immediately have at least two solutions: 1 and -1. We can eliminate Answers A, B and C.
For the last step, we have to determine what OTHER solutions are possible. You can either prove that fractions fit (try using X = 1/2) or proving that larger integers do NOT fit (try using X = 2). Either way, you can eliminate the final incorrect answer.
Final Answer:
GMAT assassins aren't born, they're made,
Rich
_________________
760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****
Rich Cohen
Co-Founder & GMAT Assassin
Special Offer:
Save $75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/