Was that really a problem?

I believe that I've given an explanation in the previous post.

You could check your answer for h = 13.9 m and h = 13.99 m, to test the convergence of the result .

To make the problem more interesting, the parameters in part 2(b) should be chosen carefully k = 28 and n = 0.5, as both take roughly the same time (15.2 hours) to fill up the container up to the water level 13.9 m. But the nonlinear control mechanism in 2(b) will fill up the container 100% by 17 hours.



In reality, the process will be terminated (turn off the valve) if time taken to fill the container exceeds the expected time. The MRO (maintenance, repair, and overhaul) team will carry out the Fault Detection and Diagnosis manually on the system. Modern systems usually have the Fault-Tolerant Control System installed to minimize downtime of a system.

This post has been edited by Critical_Fallacy: Apr 13 2015, 09:39 PM

Yes it does make sense. Thanks
I have plotted the graph in wolfram mathematica, but how to show the coordinates of maximum point in the graph?


This post has been edited by scgoh123: Apr 14 2015, 09:13 PM

Does this means that the time taken to fill up the hyperboloid container to almost full but not full?

Hi , just wondering does anybody know when does form 6 start for 2015? this year? Any ideas?

it will usually be in May~

Form 6 enrollment begins around 8 of May every year.

However, it depends on the school whether to hold orientation till June, or to begin learning session immediately.

Your first semester officially commences June.

In Mathematica, the maximum of an expression that is a function of one variable can be found with



where expr is a function of x, xo is the initial guess for the search for the minimum or maximum, xl is the lower bound for the search region, and xu is the upper bound for the search region. Both xl and xu are optional.

If you use WolframAlpha online, just type:



Then, move your mouse cursor to the red dot to display the coordinates. And that's for the first graph.



This post has been edited by Critical_Fallacy: Apr 15 2015, 01:52 PM

Hi thank you for the response . First semester starting in june? The check in date is on 5th May . So will I be starting my school teaching and learning lessons around May or June?

The linear control mechanism in 2(a) fails to fill up the water level of the tank to 100% because the amount of water it pumps into the tank is insufficient to increase the height of the water level significantly.

It is important to comment on the physical meaning of linear control mechanism, where the flow rate is linearly proportional to measured water level error Δh = (14 - h). As the height of the water level is approaching 14 m, the error signal is greatly reduced Δh ≈ 0, causing the flow rate is throttled to a state where it causes an infinitesimal increase in the water level (e.g. 13.9 m + 0.09 + 0.009 + ...), and it never reach the full tank height.

Technically, this doesn't cause overflow, but is undesirable because the water pump seems to be in perpetual operation (causing the acceleration of wear and tear, and not energy-efficient). Of course, the control system can add a constraint to terminate the pump by installing a simple fail-safe sensor at 13.9 m, if the 0.1 m does not have a significant impact on the commercial side.

Yeah I've used this method, but I can't pinpoint to maximum point on the graph. What's wrong with this?


This post has been edited by scgoh123: Apr 15 2015, 10:26 PM

Depends on the school that you're enrolled in. Usually you will start off with Orientation week.

The command "FindMaximum[]" returns only the numerical values.

You should plot the numerical evaluation of the equation and then label the result by identifying its maximum value.

(* Find maximum *)



(* Create labels *)



(* Plot and annotate results *)



As you can see, it's pretty systematic and tedious in a sense. A quick shortcut is to use the Tooltip[], which allows you to use a mouse pointer to display information about curves or data points when the mouse pointer is over a curve or a data point.

The use of computational software is probably beyond STPM. The proper way to find the maximum is to solve the following equation:

YEA.. me too... is that really the rule for stpm exampaper??

It's quite tedious, actually. Thanks for solving this problem! This really helps a lot~

my teacher said its better to follow your text..
this bcoz the "skema" exampaper, may accept & maybe not..
so to be safe,, follow directly on text..
and additonal info, 'salah media' will directly be jugde by your table..
and the max marks is 3 only..
(this by my own experience)

my tc said.. its better not..
bcause, if your 'definisi' incorrect, it may effect the mark..

I agree with that, even though your summations of data given is not tally with the sum given in the question....... (I saw this in past year papers)

RED-HAIR-SHANKS Are you there...? Long time I haven't heard replies from you.

Anyone had finished 2nd Term trial exam? Can anyone upload their papers here? I will be uploading mine soon.

Just Visiting By Can I ask a question regarding PA graphs?
I saw a word 'unjuran' in STPM 2013(?) Ulangan Paper. What does this word means? And what type of graph should I draw if the question asks for 'unjuran permintaan komoditi makanan utama pada tahun 2010 hingga 2020 (anggaran)'?