Add maths Project selangor 20150ri.pdf
Transcript of Add maths Project selangor 20150ri.pdf
Introduction
In Mathematics, maximum and minimum value of a function, known as extreme
which is the largest and smallest value that function that taken in a point whether from
its domain (extreme relative or vocal) or in the domain function as whole ( global
extreme). Pierre de Fermat is one of the first Mathematician that proposed general
technique ( adequality) for finding maximum and minimum. Finding extreme value is
the fundamental goal of optimization.
Part 1
a.
I. Mathematical optimization
An act, process, or methodology of making something (as a design, system, or
decision) as fully perfect, functional, or effective as possible using mathematical theory
or concept; specifically : the mathematical procedures (as finding the maximum of a
function) .
II.
Global Maximum :
A global maximum, also known as an absolute maximum, the largest overall value of
a set, function, etc., over its entire range.
Global Minimum
A global minimum, also known as an absolute minimum, is the smallest overall value
of a set, function, etc., over its entire range.
III.
Local Minimum :
It is the least value that locates within a set of points which may or may not be a
global minimum and it is not the lowest value in the entire set. It can also be termed as
"Relative Minimum"
Local Maximum :
It can also be expressed as "Relative Maximum". It is a greatest value in a set of
points but not highest when compared to all values in a set. The set of points can be
global maximum.
How to find
Maximum/Minimum
Quadratic equation
Method 1 : Calculus
If the quadratic is in the form y = ax2 + bx + c
The maximum or minimum value of a quadratic
function occurs at its vertex.
If a>0 is minimum., a<0 is maximum
For y = ax2 + bx + c, (c - b
2/4a) gives the y-value at its
vertex.
Method 2 : Completing square
If the quadratic is in the form y = a(x-h)2 + k
k gives us the maximum or minimum value of the
quadratic accordingly as a is negative or positive
respectively.
Method 3 : Differentiation
Using differentiation when the quadratic is in the form y = ax2+ bx + c
1. Differentiate y with respect to x. dy/dx = 2ax + b
2. Determine the differentiation point values in terms of dy/dx. It can be
found by setting these values equal to 0 and find the corresponding values.
dy/dx = 0. 2ax+b = 0, x = -b/2a
3. Substitute this value of x into y to get the minimum/maximum point
From excel, we obtain
length, width, Perimeter Area, x y (4y+2x) m^2
5 47.5 200 237.5
10 45 200 450
15 42.5 200 637.5
20 40 200 800
25 37.5 200 937.5
30 35 200 1050
35 32.5 200 1137.5
40 30 200 1200
45 27.5 200 1237.5
50 25 200 1250
55 22.5 200 1237.5
60 20 200 1200
65 17.5 200 1137.5
70 15 200 1050
75 12.5 200 937.5
80 10 200 800
85 7.5 200 637.5
90 5 200 450
95 2.5 200 237.5
100 0 200 0
Table 1
From this table, we can see dimension that can maximize the barn is
50 m × 25 m which gives total area of 1250
b)
h cm
(30-2h) cm
(30-2h) cm
Diagram 4
Volume = length × width × height
= (30-2h) × (30-2h) × h
=
= Volume , V =
؞
Part 3
I. Graph function of
t 0930 1030 1130 1230 1330 1430 1530 1630 1730 1830 1930 2030 2130 2230 2330 2430
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
P(t) 0 241.2 900 1800 2700 3359 3600 3358 2699 1799 899 240 0 242 901 1802
Graph 2
II. The peak hour reach at 1530/3.30pm, number of visitor on that hour are 3600
visitor
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
P(t) 0 241 900 1800 2700 3359 3600 3358 2699 1799 899 240 0 242 901 1802
0
500
1000
1500
2000
2500
3000
3500
4000
Vis
ito
r
P(t) Visitor versus time
Further Exploration
b)
Cabinet type Price (RM)/Unit Area ( Volume (
100 0.6 0.8
200 0.8 1.2
Table 2
I. a)
≥
≥
≤
-----------(1)
≤ ] ÷ 100
≤ -------------(2)
[ ≤ 7.2] ÷ 0.2
3 ≤ 36 ------------(3)
b)
Graph 3
II.
We need to find the value of x and y that maximize the space of cabinet.
First method – Simultaneous equation
≤ 3 ≤ 36
= ---(1) 3 =36 ------(1)
= ---(3)
3 =36
=36 =
=6>>>> =3 -------(4) =
, V
III. From excel,
combination x y Area )
Volume
( )
cost
(RM)
A 4 5 6.4 9.2 1400
B 5 4 6.2 8.8 1300
C 6 4 6.8 9.6 1400
D 7 3 6.6 9.2 1300
E 8 3 7.2 10 1400
F 9 2 7 9.6 1300
Table 3
IV. If I were Aaron, I would choose combination E (x=8, y=3)
Because the cost is exactly RM1400 and it also maximize the are 7.2 and
volume 10 with high number of combination of cabinet 11.