1 - x^2 >= 0 - multiply by (-1) to get a clearer picture:
x^2 - 1 <=0
x^2 <= 1.
This means that x is going to be between -1 and 1, with answer E
I suppose you got confused because of the way it was written: it was indeed kindda tangled...
BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course
Redeem
Featured Course
Target Test Prep GMAT OnDemand
Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.
- 715+ score guarantee — highest in the industry (99th percentile)
- 52 chapters · 1,500+ lessons · 4,000+ practice questions
- 400 hours of video · 1,500+ instructor-led HD smartboard lessons
- 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
- 24/7 live support + weekly Zoom office hours with GMAT instructors
- TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
- 1,200+ flashcards + AI-powered study assistant & daily calendar
- OnDemand, LiveTeach & GMAT Bootcamp formats available
- Also: GRE, SAT Math & Executive Assessment courses
- MBA Admissions Consulting now available
- 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
- 200,000+ students served
- 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★
5.0
(559 reviews)
130-pt guarantee
$0 to start
then $127/mo
OG 172
Source: Beat The GMAT — Problem Solving |
OR, use the a^2 - b^2 = (a+b)(a-b) formulaDanaJ wrote:1 - x^2 >= 0 - multiply by (-1) to get a clearer picture:
x^2 - 1 <=0
x^2 <= 1.
This means that x is going to be between -1 and 1, with answer E
I suppose you got confused because of the way it was written: it was indeed kindda tangled...
1-x^2 >=0
(1-x)(1+x)>=0
(1-x) >=0
-x>=-1
x<=1
(1+x)>=0
x>=-1
So therefore, -1<=x<=1
