# High-school calculus question - do I have enough information to figure out the function? **URL:** \ **Category:** Factual Questions\ **Created:** [April 6, 2015, 12:48am UTC](https://boards.straightdope.com/t/high-school-calculus-question-do-i-have-enough-information-to-figure-out-the-function/716935 "2015-04-06T00:48:26Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [April 9, 2015, 2:04am UTC](https://boards.straightdope.com/t/high-school-calculus-question-do-i-have-enough-information-to-figure-out-the-function/716935/41 "2015-04-09T02:04:34Z")
> [@D18](#): > > It doesn’t matter what n and e are. The problem gave me the three x values of the local extrema, but n and e only affect the y values, so they can be set at arbitrary values. Being lazy, I selected n = 1 and e = 0. > > I used your formula to work out the question, and I got the correct graph, but reflected in the y axis, so one of us flipped the signs. It’s probably safe to say I did! 😉 I didn’t read the OP closely enough. I thought the extrema were given as ordered pairs. If it is just the x values then you are right, it doesn’t matter. ETA: if n doesn’t matter and i, j and k are integers then I would pick n=12 to make everything clean. Also, the sign flip comes because 2 maxima and 1 minimum means the quartic is concave down so a must be negative. ---
**Author:** ![D18](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@D18](https://boards.straightdope.com/u/D18)\ **Post date:** [April 9, 2015, 2:12am UTC](https://boards.straightdope.com/t/high-school-calculus-question-do-i-have-enough-information-to-figure-out-the-function/716935/42 "2015-04-09T02:12:23Z")
Well, I’m not right. The guys upthread who told me that are right! That was my primary area of confusion when I started this whole process out. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [April 9, 2015, 3:26am UTC](https://boards.straightdope.com/t/high-school-calculus-question-do-i-have-enough-information-to-figure-out-the-function/716935/43 "2015-04-09T03:26:12Z")
> [@Leo\_Bloom](#): > > … **LSLGuy** , WTF? You don’t see anybody else in this thread flying heavy metal, do you? > [@D18](#): > > … **Leo** , […] it may be a woosh, but why are you calling out **LSLGuy**? His post was really helpful! It’s not fair that **LSLGuy** gets to be smart in calculus _and_ fly F-16s and 747s. ---
**Author:** ![D18](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@D18](https://boards.straightdope.com/u/D18)\ **Post date:** [April 9, 2015, 1:17pm UTC](https://boards.straightdope.com/t/high-school-calculus-question-do-i-have-enough-information-to-figure-out-the-function/716935/44 "2015-04-09T13:17:09Z")
Ah! ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 10, 2015, 2:19am UTC](https://boards.straightdope.com/t/high-school-calculus-question-do-i-have-enough-information-to-figure-out-the-function/716935/45 "2015-04-10T02:19:06Z")
> [@Leo\_Bloom](#): > > It’s not fair that **LSLGuy** gets to be smart in calculus _and_ fly F-16s and 747s. I’m not that smart in calculus. I did have a math minor as an undergrad, but that was damn near 40 years ago. What I can do for some folks sometimes on some topics is bridge the gap between the true experts speaking and the folks who can’t articulate a clear question or recognize their own implicit assumptions. In other words I like to think I’m good at arm-waving level explanations with lots of simplifying assumptions. You’ll notice of the two very small points I added here, one was promptly (and rightly) dissected & declared wrong by the true expert: the eminently distinguished & highly esteemed (but thoroughly mis-named) **indistinguishable**. I’ve never flown a 747 and the odds are very, very small I ever will. So thanks for the kind words, and I know you mean well, but you’re 1 for 3 this time. And even the F16s were now over 25 years ago. One suddenly feels old. It’s past my bedtime; off to enjoy my fiber supplement & prepare for bed. [Previous page](https://boards.straightdope.com/t/high-school-calculus-question-do-i-have-enough-information-to-figure-out-the-function/716935.md?page=2)