Lesson: Graphs of Quadratics

Comment on Graphs of Quadratics

Brent,

Could you explain me the exercise 316 (OG 2017) in a different way from the OG solution?

Thanks,
Pedro
gmat-admin's picture

Brent,

Exercise 335 from OG 2017. I didn't understand why statement 1 is sufficient. If the y-coordinate of point R is -3, ok, they are equidistant, but if the y-coordinate of point R is -1, so (-1,-1) is not equidistant from (-3,-3), right?

Could you explain me where I'm wronging?

Thanks,
Pedro
gmat-admin's picture

Hi Pedro,

As long as x = -1, point R will ALWAYS be equidistant from (-3, -3) and (1, -3)

For example, (-1, 0) is equidistant from (-3, -3) and (1, -3)
And (-1, 22) is equidistant from (-3, -3) and (1, -3)
And (-1, -1) is equidistant from (-3, -3) and (1, -3)
And (-1, -7) is equidistant from (-3, -3) and (1, -3)
etc.

I explain why this is the case in my solution here: https://gmatclub.com/forum/in-the-xy-coordinate-plane-is-point-r-equidis...

Hi Brent,

I was clueless about the concept in play for this Q : https://gmatclub.com/forum/the-figure-shows-the-graph-of-y-x-1-x-1-2-in-the-xy-160785.html

Furthermore I couldn't understand cases 3 to 6 posted by a student(keats) at this link : https://gmatclub.com/forum/the-figure-shows-the-graph-of-y-x-1-x-1-2-in-the-xy-160785.html?sid=0fcda6e802211f7e797bed41ed3e8bec#p1739406

Need your help in clarifying this concept.

Thanks & Regards,
Abhirup
gmat-admin's picture

Hi Abhirup,

Here's my solution to the question: https://gmatclub.com/forum/the-figure-shows-the-graph-of-y-x-1-x-1-2-in-...

The user (at https://gmatclub.com/forum/the-figure-shows-the-graph-of-y-x-1-x-1-2-in-...) is reciting some translation properties that many students learn in high school.

Don't worry about them. The GMAT does not expect you to know them.
Instead, just familiarize yourself with my solution, and you'll have a strategy for similar questions.

That said, this question type is VERY rare. In fact, I'd venture to say that 1 student out of 500 would see a question like this on test day.

Cheers,
Brent

Thanks a lot for that brilliant explanation!! So to sum up, whenever I come across any such problem I need to find the points and graph the equation. Doing this will give me a clearer picture.

Regards,
Abhirup
gmat-admin's picture

Yes, that approach will help you determine the position/shape of one curve compared to the other curve.

https://gmatclub.com/forum/m24-184377.html
please explain
gmat-admin's picture

https://gmatclub.com/forum/a-parabola-in-the-coordinate-geometry-plane-is-represented-by-the-equa-273986.html

Can you please help me with this problem?
Is there any rule I should know on parabola and line intersecting?
gmat-admin's picture

I'm not crazy about this question.
For one, the wording of statement 2 is somewhat ambiguous.
Also, the question is teetering on the edge of being beyond the scope of the GMAT.

Having said all that, here's my full solution: https://gmatclub.com/forum/a-parabola-in-the-coordinate-geometry-plane-i...

Office Hours

Have questions about your preparation or an upcoming test? Need help modifying the Study Plan to meet your unique needs? No problem. Just book a Skype meeting with Brent to discuss these and any other questions you may have. 

Change Playback Speed

You have the option of watching the videos at various speeds (25% faster, 50% faster, etc). To change the playback speed, click the settings icon on the right side of the video status bar.

Have a question about this video?

Post your question in the Comment section below, and a GMAT expert will answer it as fast as humanly possible.

Free “Question of the Day” emails!