Last visit was: 17 Jun 2024, 06:35 It is currently 17 Jun 2024, 06:35

Close

GRE Prep Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Own Kudos [?]: 2994 [4]
Given Kudos: 172
Location: India
WE:Education (Education)
Send PM
Most Helpful Community Reply
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Own Kudos [?]: 2994 [1]
Given Kudos: 172
Location: India
WE:Education (Education)
Send PM
General Discussion
Retired Moderator
Joined: 19 Nov 2020
Posts: 326
Own Kudos [?]: 358 [1]
Given Kudos: 64
GRE 1: Q160 V152
Send PM
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Own Kudos [?]: 2994 [1]
Given Kudos: 172
Location: India
WE:Education (Education)
Send PM
Re: The graph of a quadratic function f(x) passes through (9, 0), (0, 9), [#permalink]
1
motion2020 wrote:
so, it's y-intercept is 9 from (0,9) and one of the roots is 9 from (9,0)
\((x-9)(x-1)=0\) is the present equation's root form and it's quadratic equation form is \(x^2-10x+9=0\)
let's check equation with pair (7, 30) ---> 49-70+9=-12 :( did not work
also, the axis of symmetry is a vertical line x=−b/2a, and spoiler suggests x=17/4
then quadratic equation must be in the form \(2x^2-17x+9=0\)
plugging (7,30) into the above equation derived from the axis of symmetry equation, results in \(2*49-17*7+9=-12\) not 30 :(

KarunMendiratta wrote:
The graph of a quadratic function f(x) passes through (9, 0), (0, 9), and (7, 30). What is the equation of axis of symmetry of f(x)?

Show: ::
\(x = \frac{17}{4}\)


How do you know \(a > 0\)??
Retired Moderator
Joined: 19 Nov 2020
Posts: 326
Own Kudos [?]: 358 [1]
Given Kudos: 64
GRE 1: Q160 V152
Send PM
Re: The graph of a quadratic function f(x) passes through (9, 0), (0, 9), [#permalink]
1
then period, does not this question's formulation violate the definition of quadratic function?

a quadratic function is a function that can be written in the form \(f(x)=ax^2+bx+c\) where a, b, and c are real numbers and a≠0

KarunMendiratta wrote:
motion2020 wrote:
so, it's y-intercept is 9 from (0,9) and one of the roots is 9 from (9,0)
\((x-9)(x-1)=0\) is the present equation's root form and it's quadratic equation form is \(x^2-10x+9=0\)
let's check equation with pair (7, 30) ---> 49-70+9=-12 :( did not work
also, the axis of symmetry is a vertical line x=−b/2a, and spoiler suggests x=17/4
then quadratic equation must be in the form \(2x^2-17x+9=0\)
plugging (7,30) into the above equation derived from the axis of symmetry equation, results in \(2*49-17*7+9=-12\) not 30 :(

KarunMendiratta wrote:
The graph of a quadratic function f(x) passes through (9, 0), (0, 9), and (7, 30). What is the equation of axis of symmetry of f(x)?

Show: ::
\(x = \frac{17}{4}\)


How do you know \(a > 0\)??
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Own Kudos [?]: 2994 [2]
Given Kudos: 172
Location: India
WE:Education (Education)
Send PM
Re: The graph of a quadratic function f(x) passes through (9, 0), (0, 9), [#permalink]
2
motion2020 wrote:
then period, does not this question's formulation violate the definition of quadratic function?

a quadratic function is a function that can be written in the form \(f(x)=ax^2+bx+c\) where a, b, and c are real numbers and a≠0



No. \(-2\) is a real number only
User avatar
GRE Prep Club Legend
GRE Prep Club Legend
Joined: 07 Jan 2021
Posts: 4603
Own Kudos [?]: 69 [0]
Given Kudos: 0
Send PM
Re: The graph of a quadratic function f(x) passes through (9, 0), (0, 9), [#permalink]
Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Prep Club for GRE Bot
[#permalink]
Moderators:
Moderator
1088 posts
GRE Instructor
218 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne