User:Pingusam

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EQUATION

3x +  2y - 3z = -5\,
4x + 3y - 4z = -8\,
-5x -  4y +  4z = 9\,
B = \begin{bmatrix}
3 & 2 & -3 &   | & 1 & 0 & 0  \\
4 & 3 & -4 &   | & 0 & 1 & 0  \\
-5 & -4 & 4 & | &  0 & 0 & 1
\end{bmatrix}
B = \begin{bmatrix}
-3 & -4 & 0 &   | & 4 & 0 & 3  \\
4 & 3 & -4 &   | & 0 & 1 & 0  \\
-5 & -4 & 4 & | &  0 & 0 & 1
\end{bmatrix}
B = \begin{bmatrix}
-3 & -4 & 0 &   | & 4 & 0 & 3  \\
-1 & -1 & 0 &   | & 0 & 1 & 1  \\
-5 & -4 & 4 & | &  0 & 0 & 1
\end{bmatrix}
B = \begin{bmatrix}
-3 & -4 & 0 &   | & 4 & 0 & 3  \\
0 & 1 & 0 &   | & -4 & 3 & 0  \\
-5 & -4 & 4 & | &  0 & 0 & 1
\end{bmatrix}
B = \begin{bmatrix}
-3 & -4 & 0 &   | & 4 & 0 & 3  \\
0 & 1 & 0 &   | & -4 & 3 & 0  \\
0 & -8 & -12 & | &  20 & 0 & 12
\end{bmatrix}
B = \begin{bmatrix}
-3 & -4 & 0 &   | & 4 & 0 & 3  \\
0 & 1 & 0 &   | & -4 & 3 & 0  \\
0 & 0 & -12 & | &  -12 & 24 & 12
\end{bmatrix}
B = \begin{bmatrix}
-3 & 0 & 0 &   | & -12 & 12 & 3  \\
0 & 1 & 0 &   | & -4 & 3 & 0  \\
0 & 0 & -12 & | &  -12 & 24 & 12
\end{bmatrix}
B = \begin{bmatrix}
1 & 0 & 0 &   | & 4 & -4 & -1  \\
0 & 1 & 0 &   | & -4 & 3 & 0  \\
0 & 0 & 1 & | &  1 & -2 & -1
\end{bmatrix}
B^{-1} = \begin{bmatrix}
4 & -4 & -1  \\
-4 & 3 & 0  \\
1 & -2 & -1
\end{bmatrix}

\begin{bmatrix}
x \\
y \\
z\end{bmatrix}
=
\begin{bmatrix}
4 & -4 & -1  \\
-4 & 3 & 0  \\
1 & -2 & -1
\end{bmatrix}
\begin{bmatrix}
-5 \\
-8  \\
9 
\end{bmatrix}
=
\begin{bmatrix}
3 \\
-4 \\
2\end{bmatrix}

x = 3\,
y=-4\,
z=2\,


ECHELON

6x +  y + 2z = 5\,
8x + 3y + 4z = 5\,
2x -  y -  z = 6\,
A = \begin{bmatrix}
6 & 1 & 2 &   | & 5  \\
8 & 3 & 4 &   | &  5 \\
2 & -1 & -1 & | &  6
\end{bmatrix}
A = \begin{bmatrix}
8 & 0 & 1 &   | & 11  \\
8 & 3 & 4 &   | &  5 \\
2 & -1 & -1 & | &  6
\end{bmatrix}
A = \begin{bmatrix}
8 & 0 & 1 &   | & 11  \\
8 & 3 & 4 &   | &  5 \\
14 & 0 & 1 & | &  23
\end{bmatrix}
A = \begin{bmatrix}
8 & 0 & 1 &   | & 11  \\
0 & 3 & 3 &   | &  -6 \\
14 & 0 & 1 & | &  23
\end{bmatrix}
A = \begin{bmatrix}
-6 & 0 & 0 &   | & -12  \\
0 & 3 & 3 &   | &  -6 \\
14 & 0 & 1 & | &  23
\end{bmatrix}
A = \begin{bmatrix}
1 & 0 & 0 &   | & 2  \\
0 & 3 & 3 &   | &  -6 \\
14 & 0 & 1 & | &  23
\end{bmatrix}
x +  0y + 0z = 2\,
0x + 3y + 3z = -6\,
14x +  0y   z = 23\,
x = 2\, as [1]\,
3y + 3z = -6\, as [2]\,
14x + z = 23\, as [3]\,

Substituting [1]\, in to [3]\,

14(2) + z = 23\,
28 + z = 23\,
z = -5\, as [4]\,

Substituting [4]\, in to [2]\,

3y + 3(-5) = -6\,
3y -15 = -6\,
3y = 9\,
y  = 3\,

MAGIC SQUARE

a +  g = 13\,
c +  e = 13\,
b +  f = 26\,
d +  h = 24\,
a +  b = 11\,
c +  d = 15\,
e +  f = 25\,
g +  h = 25\,
e +  g = 21\,
a +  c + f+h = 34\,

M=  \begin{bmatrix}
    1 & 0 & 1 & 0 & 0 & 1 & 0 & 1\\
    1 & 1 & 0 & 0 & 0 & 0 & 0 & 0\\
    0 & 0 & 1 & 1 & 0 & 0 & 0 & 0\\
    0 & 0 & 0 & 0 & 1 & 1 & 0 & 0\\
    0 & 0 & 0 & 0 & 0 & 0 & 1 & 1\\
    0 & 1 & 0 & 0 & 0 & 1 & 0 & 0\\
    0 & 0 & 0 & 1 & 0 & 0 & 0 & 1\\
    0 & 0 & 1 & 0 & 1 & 0 & 0 & 0\\
  \end{bmatrix}


A= \begin{bmatrix}
34\\
11\\
15\\
25\\
25\\
26\\
24\\
13
\end{bmatrix}

\begin{bmatrix}
    1 & 0 & 1 & 0 & 0 & 1 & 0 & 1\\
    1 & 1 & 0 & 0 & 0 & 0 & 0 & 0\\
    0 & 0 & 1 & 1 & 0 & 0 & 0 & 0\\
    0 & 0 & 0 & 0 & 1 & 1 & 0 & 0\\
    0 & 0 & 0 & 0 & 0 & 0 & 1 & 1\\
    0 & 1 & 0 & 0 & 0 & 1 & 0 & 0\\
    0 & 0 & 0 & 1 & 0 & 0 & 0 & 1\\
    0 & 0 & 1 & 0 & 1 & 0 & 0 & 0\\
  \end{bmatrix}
\begin{bmatrix}
34\\
11\\
15\\
25\\
25\\
26\\
24\\
13
\end{bmatrix}
=
\begin{bmatrix}
a\\
b\\
c\\
d\\
e\\
f\\
g\\
h
\end{bmatrix}

\begin{bmatrix}
a\\
b\\
c\\
d\\
e\\
f\\
g\\
h
\end{bmatrix}
=
\begin{bmatrix}
1\\
10\\
4\\
11\\
9\\
16\\
12\\
13
\end{bmatrix}


MATHS B QUESTION 1 A


y = 2(x-4)^3 - 7\,
y = 2((x-4)(x-4)(x-4)) - 7\,
y = 2((x^2-8x+16)(x-4)) - 7\,
y = 2(x^3 - 4x^2 - 8x^2 + 32x + 16x -64)-7\,
y = 2x^3 - 8x^2 - 16x^2 + 64x + 32x - 128 - 7\,
y = 2x^3 -24x^2 + 96x -135\,
a = 2\,
b = -24\,
c = 96\,
d = -135\,

MATHS C LAST QUESTION

A = \begin{bmatrix}
360\div1400 & 40\div1700 & 400\div2000  \\
240\div1400 & 160\div1700 & 520\div2000  \\
50\div1400 & 650\div1700 & 430\div2000 
\end{bmatrix}
 = \begin{bmatrix}
9\div35 & 40\div85 & 1\div5  \\
6\div35 & 8\div85 & 13\div50  \\
1\div28 & 1\div34 & 43\div200 
\end{bmatrix}
 D= \begin{bmatrix}
800  \\
900  \\
1000
\end{bmatrix}
 P.Inp.= \begin{bmatrix}
750  \\
850  \\
650
\end{bmatrix}
 Labour= \begin{bmatrix}
750\times  .8\\
850\times.6  \\
650\times.7
\end{bmatrix}
 = \begin{bmatrix}
600\\
510  \\
455
\end{bmatrix}

X = (I_3 - A)^{-1} D\,

X = \begin{bmatrix}
1766.40\\
1995.42  \\
2326.17
\end{bmatrix}
New Labour = \begin{bmatrix}
1766.40\times(3\div7)\\
1995.42\times.3  \\
2326.17\times.2275
\end{bmatrix}
= \begin{bmatrix}
756.86\\
598.63  \\
529.20
\end{bmatrix}

EQUATION

-2x -  2y + 3z = -5\,
6x + 5y - 8z = -8\,
-3x -  y +  3z = 9\,
Q = \begin{bmatrix}
-2 & -2 & 3 \\
6 & 5 & -8 \\
-3 & -1 & 3
\end{bmatrix}

{det}Q = 
( -2 \times {det}\begin{bmatrix}
5 & -8\\
-1 & 3 \\
\end{bmatrix})

-

( -2 \times {det}\begin{bmatrix}
6 & -8\\
-3 & 3 \\
\end{bmatrix})

+

( 3 \times {det}\begin{bmatrix}
6 & 5\\
-3 & -1 \\
\end{bmatrix})

{det}Q = (-2 \times ((5 \times 3) - (-8 \times -1)))

-

(-2 \times ((6 \times 3) - (-8 \times -3)))

+

(3 \times ((6 \times -1) - (5 \times -3)))

{det}Q = (-2 \times 7) - (-2 \times -6) + (3 \times 9)
{det}Q = 1\,

↔↔↔↔↔↔↔↔↔↔↔↔

Q_x = \begin{bmatrix}
-3 & -2 & 3 \\
5 & 5 & -8 \\
5 & -1 & 3
\end{bmatrix}


{det}Q_x = 
( -3 \times {det}\begin{bmatrix}
5 & -8\\
-1 & 3 \\
\end{bmatrix})

-

( -2 \times {det}\begin{bmatrix}
5 & -8\\
5 & 3 \\
\end{bmatrix})

+

( 3 \times {det}\begin{bmatrix}
5 & 5\\
5 & -1 \\
\end{bmatrix})


{det}Q_x = (-2 \times ((5 \times 3) - (-8 \times -1)))

-

(-2 \times ((5 \times 3) - (-8 \times 5)))

+

(3 \times ((5 \times -1) - (5 \times 5)))


{det}Q_x = (-3 \times 7) - (-2 \times 55) + (3 \times -30)
{det}Q = -1\,

↔↔↔↔↔↔↔↔↔↔↔↔

Q_y = \begin{bmatrix}
-2 & -3 & 3 \\
6  & 5 & -8 \\
-3 & 5 & 3
\end{bmatrix}


{det}Q_y = 
( -3 \times {det}\begin{bmatrix}
5 & -8\\
-1 & 3 \\
\end{bmatrix})

-

( -3 \times {det}\begin{bmatrix}
6 & -8\\
-3 & 3 \\
\end{bmatrix})

+

( 3 \times {det}\begin{bmatrix}
6 & 5\\
-3 & 5 \\
\end{bmatrix})


{det}Q_y = (-2 \times ((5 \times 3) - (-8 \times 5)))

-

(-3 \times ((6 \times 3) - (-8 \times -3)))

+

(3 \times ((6 \times 5) - (5 \times -3)))


{det}Q_y = (-2 \times 55) - (-3 \times -6) + (3 \times 45)
{det}Q_y = 7\,

↔↔↔↔↔↔↔↔↔↔↔↔

Q_z = \begin{bmatrix}
-2 & -2 & -3 \\
6  & 5 & 5 \\
-3 & -1 & 5
\end{bmatrix}


{det}Q_z = 
( -2 \times {det}\begin{bmatrix}
5 & 5\\
-1 & 5 \\
\end{bmatrix})

-

( -2 \times {det}\begin{bmatrix}
6 & 5\\
-3 & 5 \\
\end{bmatrix})

+

( -3 \times {det}\begin{bmatrix}
6 & 5\\
-3 & -1 \\
\end{bmatrix})


{det}Q_z = (-2 \times ((5 \times 5) - (-1 \times 5)))

-

(-2 \times ((6 \times 5) - (5 \times -3)))

+

(-3 \times ((6 \times -1) - (5 \times -3)))


{det}Q_z = (-2 \times 30) - (-2 \times 45) + (-3 \times 7)
{det}Q_z = 3\,

C = \begin{bmatrix}
1 & 1 & 2  \\
2 & 2 & 3 \\
2 & 3 & 3
\end{bmatrix}
C^t = \begin{bmatrix}
1 & 2 & 2  \\
1 & 2 & 3 \\
2 & 3 & 3
\end{bmatrix}
C^t = \begin{bmatrix}
1 & 2 & 2 & | & 140  \\
1 & 2 & 3 & | & 150  \\
2 & 3 & 3 & | & 210
\end{bmatrix}
C^t = \begin{bmatrix}
1 & 2 & 0 & | & 120  \\
1 & 2 & 3 & | & 150  \\
2 & 3 & 3 & | & 210
\end{bmatrix}
C^t = \begin{bmatrix}
1 & 2 & 0 & | & 120  \\
-1 & -1 & 0 & | & -60  \\
2 & 3 & 3 & | & 210
\end{bmatrix}
C^t = \begin{bmatrix}
-1 & 0 & 0 & | & 0  \\
-1 & -1 & 0 & | & -60  \\
2 & 3 & 3 & | & 210
\end{bmatrix}
-a +  0f + 0q = 0\,
-a - f + 0q = -60\,
2a +  2f +  3q = 210\,
a = 0\, as [1]\,
a + y = 60\, as [2]\,
2a +  3f +  3q = 210\, as [3]\,

Substituting [1]\, in to [2]\,:

1(0) + y = 60\,
y = 60\, as [4]\,

Substituting [1]\, and [4]\,: in to [2]\,:

2(0) +  3(60) +  3q = 210\,
180 +  3q = 210\,
3q = 30\,
q = 10\,
a = 0\,, y = 60\,, q = 10\,