My Math Forum A 15 year old's math assignment has me stumped... any help?

 Elementary Math Fractions, Percentages, Word Problems, Equations, Inequations, Factorization, Expansion

January 10th, 2018, 01:12 PM   #1
Member

Joined: Nov 2012
From: The Netherlands

Posts: 40
Thanks: 2

A 15 year old's math assignment has me stumped... any help?

Hi All

my kid wants my help here, but I am stumped too.
The function(pl. see image) given has p & q as variables.

- the graph has the horizontal asymptote line y = -3
-the graph intersects at (-1,5)

find P and q.

Attached Images
 mth.jpg (84.7 KB, 17 views)

January 10th, 2018, 01:31 PM   #2
Math Team

Joined: Jul 2011
From: Texas

Posts: 3,034
Thanks: 1621

$p$ and $q$ are unknown constants ... $x$ and $f(x)$ are the variables

$f(x) = \dfrac{p}{2x+1} - q$

Quote:
 - the graph has the horizontal asymptote line y = -3
$\displaystyle \lim_{x \to \infty} f(x) = -3 \implies q=3$ (why?)

Quote:
 - the graph intersects at (-1,5)
$5 = \dfrac{p}{2(-1)+1} - 3$

... solve for $p$

 January 10th, 2018, 01:59 PM #3 Member   Joined: Nov 2012 From: The Netherlands Posts: 40 Thanks: 2 You posed this to me: q=3 (why?) I wish I could tell you why ...but I am too out of touch here. I have passed it on to the kid and I hope he can find the why himself (after all, you have completely solved it all, & p =-8). * note: as I wrote, he showed me the why on his graph machine . the graph will otherwise be a +ve graph never touching 3. I think he got it ...and that's what counts. It was Fun! Thank You! Last edited by skipjack; January 10th, 2018 at 04:42 PM.
 January 10th, 2018, 04:46 PM #4 Global Moderator   Joined: Dec 2006 Posts: 21,028 Thanks: 2259 A graph machine? Thanks from Joppy
 January 11th, 2018, 02:29 AM #5 Member   Joined: Nov 2012 From: The Netherlands Posts: 40 Thanks: 2 I know..that sounded prehistoric it's his Casio Fx-9860GII Thanks from Joppy Last edited by hello_math; January 11th, 2018 at 02:33 AM.

 Tags assignment, math, stumped, year

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post Math whiz Elementary Math 21 November 19th, 2018 06:45 PM tonytwist007 Elementary Math 13 November 18th, 2018 12:07 PM IqbalHamid Math 5 April 16th, 2016 09:27 PM Ben Parker Algebra 2 August 10th, 2014 08:19 PM helpers Algebra 3 May 9th, 2009 12:40 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top