• 7 CATs FREE!
If you earn 100 Forum Points

Engage in the Beat The GMAT forums to earn
100 points for $49 worth of Veritas practice GMATs FREE VERITAS PRACTICE GMAT EXAMS Earn 10 Points Per Post Earn 10 Points Per Thanks Earn 10 Points Per Upvote If the parabola represented by f(x) = ax^2 + bx + c tagged by: VJesus12 This topic has 1 expert reply and 0 member replies If the parabola represented by f(x) = ax^2 + bx + c If the parabola represented by f(x) = ax^2 + bx + c passes through points (-3,0) , (0,3) and (5,0), which of the following must be true? I. f(-1) > f(2) II. f(1) > f(0) III. f(2) > f(1) A. Only I B. Only II C. Only III D. I and II E. I and III The OA is B. Do I need to make the graph of the parabola? Is there another way to solve this PS question? Experts, I would like some help. GMAT/MBA Expert Legendary Member Joined 20 Jul 2017 Posted: 503 messages Followed by: 10 members Upvotes: 86 GMAT Score: 770 On this problem, doing a quick sketch could be really useful to visualize the information you have, but it isn't strictly necessary. We know that the parabola passes through both (-3,0) and (5,0). Since these points both have the same y-coordinate, we know that the vertex of the graph must have an x-coordinate that is directly between these two points. This gives us an x-coordinate of 1 for the vertex. We also know that our parabola can either face up or down, so all of the points between (-3,0) and (5,0) must either fall above the x-axis or below the x-axis. Our third point tells us that (0,3) is on the graph. This point comes between (-3,0) and (5,0), and it falls above the x-axis. This means that our vertex must be above the x-axis, our vertex must be the highest point on our graph, and our parabola must be facing down. Using that information, we can evaluate each of the statements. I. f(-1) is farther from our vertex [f(1)] than f(2). This means it is farther down the parabola, making f(-1) < f(2). FALSE. II. f(1) is the vertex on a downwards facing parabola, so it is the highest point on our graph. So f(1) > f(anything). TRUE. III. Again, f(1) is the highest point on the graph, so nothing can be > f(1). FALSE. This gives B as the correct answer! If you had trouble following any of this, let me know, and I can demonstrate with diagrams. _________________ Erika John - Content Manager/Lead Instructor https://gmat.prepscholar.com/gmat/s/ Get tutoring from me or another PrepScholar GMAT expert: https://gmat.prepscholar.com/gmat/s/tutoring/ Learn about our exclusive savings for BTG members (up to 25% off) and our 5 day free trial Check out our PrepScholar GMAT YouTube channel, and read our expert guides on the PrepScholar GMAT blog • FREE GMAT Exam Know how you'd score today for$0

Available with Beat the GMAT members only code

• Award-winning private GMAT tutoring
Register now and save up to \$200

Available with Beat the GMAT members only code

• 1 Hour Free
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Get 300+ Practice Questions

Available with Beat the GMAT members only code

• 5-Day Free Trial
5-day free, full-access trial TTP Quant

Available with Beat the GMAT members only code

• Free Trial & Practice Exam
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Free Veritas GMAT Class
Experience Lesson 1 Live Free

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

• 5 Day FREE Trial
Study Smarter, Not Harder

Available with Beat the GMAT members only code

• Free Practice Test & Review
How would you score if you took the GMAT

Available with Beat the GMAT members only code

Top First Responders*

1 Brent@GMATPrepNow 69 first replies
2 fskilnik@GMATH 54 first replies
3 Jay@ManhattanReview 48 first replies
4 GMATGuruNY 35 first replies
5 Rich.C@EMPOWERgma... 31 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

Most Active Experts

1 fskilnik@GMATH

GMATH Teacher

128 posts
2 Brent@GMATPrepNow

GMAT Prep Now Teacher

101 posts
3 Max@Math Revolution

Math Revolution

92 posts
4 Jay@ManhattanReview

Manhattan Review

86 posts
5 Rich.C@EMPOWERgma...

EMPOWERgmat

78 posts
See More Top Beat The GMAT Experts