**ssclark** Black and Proud 14178 Posts user info edit post |
Hello everyone !! I'm in search of math help. I can't for the life of me figure out what to do
can ya'll help me find the difference quotient of this function ?
5/19/2016 9:28:24 PM |

**bbehe** Burn it all down. 18330 Posts user info edit post |
but that is the difference quotient... 5/19/2016 10:24:18 PM |

**ssclark** Black and Proud 14178 Posts user info edit post |
well that will sure make the problem easier. 5/19/2016 10:53:51 PM |

**Cabbage** All American 1969 Posts user info edit post |
Yeah, what you posted is not the function, that IS the difference quotient of the function 1/(3x).
Looks like what you really want is to simplify it. What you should do first is subtract the two fractions in the top by getting a common denominator. Does that help? 5/20/2016 1:13:15 AM |

**krallum2016** All American 1356 Posts user info edit post |
2 variables? infinite solutions. 5/20/2016 3:54:56 PM |

**0EPII1** All American 42428 Posts user info edit post |
If you need extensive help for the course, look me up on http://www.tutormatchingservice.com -- I am probably the top earner for the site! Send me a message here. 5/21/2016 3:58:35 AM |

**krallum2016** All American 1356 Posts user info edit post |
Smath can you help? Please? 5/24/2016 5:05:40 PM |

**PaulISdead** All American 8348 Posts user info edit post |
OP consider yourself lucky. My AP calc class just jumped to the rule without so much of a single example.
[Edited on May 25, 2016 at 6:55 PM. Reason : The limit as h approaches zero of -1/3x^2+3h] 5/25/2016 6:54:07 PM |

**LastInACC** All American 1843 Posts user info edit post |
its tree fiddy. 5/27/2016 11:43:35 AM |

**Cherokee** All American 8258 Posts user info edit post |
PEMDAS 5/28/2016 10:49:15 PM |

**krallum2016** All American 1356 Posts user info edit post |
theres an app for this 6/6/2016 11:19:48 AM |

**FykalJpn** All American 17208 Posts user info edit post |
Wtf is a difference quotient--is that just a fraction? Fuck math, you're never gonna use it anyway. 6/6/2016 6:43:52 PM |

**krallum2016** All American 1356 Posts user info edit post |
The difference quotient anwsers the question: How much did the results change in a function over a small increment of time. If that increment of time ~~is~~ approaches 0 then you get the derivative... for certain functions...
[Edited on June 7, 2016 at 10:15 AM. Reason : ] 6/7/2016 10:14:29 AM |

**FykalJpn** All American 17208 Posts user info edit post |
So it's the slope written retardedly... 6/7/2016 11:37:44 AM |

**krallum2016** All American 1356 Posts user info edit post |
Well he posted a homework problem, so its not a 'pure' mathematical expression of the difference quotient. Its a stepping stone to doing differential equations where there are multiple functions or multiple unknowns. In that case, its not necessarily as trivial to find what you have called the slope but it is easy to expand this general format to more complex blah blah blah 6/7/2016 11:45:36 AM |

**Cabbage** All American 1969 Posts user info edit post |
^^It is the slope. Not sure what you find "retarded" about it. How else are you gonna write the slope between two points on a function f(x)? 6/7/2016 5:42:31 PM |

**FykalJpn** All American 17208 Posts user info edit post |
m = 5
seems a lot simpler than
m = (1/(3 x+3 h)-1/(3 x))/h where h = 1 and x = sqrt(11/15)/2-1/2
[Edited on June 7, 2016 at 7:54 PM. Reason : Maybe it's just me] 6/7/2016 7:38:52 PM |

**Cabbage** All American 1969 Posts user info edit post |
But m=5 is the result of some calculation, not the definition: How do you actually arrive at the result 5? That's what this is about--The process, not simply the final result.
What's the slope between the points x=1 and x=2 on the function f(x)=1/(3x)?
Sure, the answer is -1/6, but how do you actually arrive at that answer?
The way you do it is by doing [f(2)-f(1)] / (2 - 1)
That's the difference quotient.
Similarly, on the highway: if at 3:12PM you're at milepost 17, and then at 3:30PM you're at milepost 40, what's you average speed during that time?
Again, you do a difference quotient: [40 - 17] / (30 - 12) = about 1.28 miles per minute.
If that's retarded, do you have a non-retarded way of doing it? 6/7/2016 8:37:30 PM |

**FykalJpn** All American 17208 Posts user info edit post |
GPS 6/7/2016 9:05:41 PM |

**Cabbage** All American 1969 Posts user info edit post |
Oh, so you're just trying to be a smartass, huh?
Maybe you can find an app that will do that for you, too. 6/7/2016 9:55:36 PM |

**0EPII1** All American 42428 Posts user info edit post |
Quote : | "m = 5
seems a lot simpler than
m = (1/(3 x+3 h)-1/(3 x))/h where h = 1 and x = sqrt(11/15)/2-1/2" |
I can't even.... 6/8/2016 1:27:00 AM |

**krallum2016** All American 1356 Posts user info edit post |
Quote : | "where h = 1 and x = sqrt(11/15)/2-1/2" |
glad you could answer your question for yourself
[Edited on June 8, 2016 at 11:16 AM. Reason : ]6/8/2016 11:15:47 AM |

**JeffreyBSG** All American 10165 Posts user info edit post |
I think forcing students to evaluate difference quotients is mildly retarded 7/29/2016 8:39:03 PM |

**PaulISdead** All American 8348 Posts user info edit post |
One time, a retard who convinced the state of north carolina they could teach high school calculus, tried to skip this step and IMHO was wrong in doing so. 7/29/2016 9:28:15 PM |

**PaulISdead** All American 8348 Posts user info edit post |
it bugs me they distributed the 3 should have kept 3(x+h) for the problem statement
[Edited on July 30, 2016 at 10:13 AM. Reason : .] 7/30/2016 10:13:16 AM |

**justinh524** Sprots Talk Mod 25396 Posts user info edit post |
Lol this thread made me realize i remember nothing about calculus. 8/12/2016 1:24:46 PM |

**JeffreyBSG** All American 10165 Posts user info edit post |
^^ I think they're trying to be tricky 8/15/2016 12:29:55 AM |