मराठी
महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता १२ वी

Solve the following system of equations by using inversion method x + y = 1, y + z = 53, z + x = 43 - Mathematics and Statistics

Advertisements
Advertisements

प्रश्न

Solve the following system of equations by using inversion method

x + y = 1, y + z = `5/3`, z + x = `4/3`

बेरीज
Advertisements

उत्तर

Matrix form of the given system of equations is

`[(1, 1, 0),(0, 1, 1),(1, 0, 1)] [(x),(y),(z)] [(1),(5/3),(4/3)]`

This is of the form AX = B,

where A = `[(1, 1, 0),(0, 1, 1),(1, 0, 1)]` X = `[(x),(y),(z)]` B = `[(1),(5/3),(4/3)]`

Pre-multiplying AX = B by A−1, we get

A−1(AX) = A−1B

∴ (A−1A)X = A−1B

∴ IX = A−1B

∴ X = A−1B      .......(i)

To determine X, we have to find A−1

|A| = `1|(1, 1),(0, 1)| - 1|(0, 1),(1, 1)| + 0`

= 1(1 – 0) –1(0 – 1)

= 1 + 1

= 2 ≠ 0

∴ A−1 exists.

Consider, AA−1 = I

∴ `[(1, 1, 0),(0, 1, 1),(1, 0, 1)]` A−1 = `[(1, 0, 0),(0, 1, 0),(0, 0, 1)]`

Applying R3 → R3 – R1, we get

`[(1, 1, 0),(0, 1, 1),(1, -1, 1)]` A−1 = `[(1, 0, 0),(0, 1, 0),(-1, 0, 1)]`

Applying R2 → R2 − R3, we get

`[(1, 1, 0),(0, 2, 0),(0, -1, 1)]` A−1 = `[(1, 0, 0),(1, 1, -1),(-1, 0, 1)]`

Applying R1 → `(1/2)` R2, we get

`[(1, 1, 0),(0, 1, 0),(0, -1, 1)]` A−1 = `[(1, 0, 0),(1/2, 1/2, -1/2),(-1, 0, 1)]`

Applying R1 → R1 − R2, we get

`[(1, 1, 0),(0, 1, 0),(0, -1, 1)]` A−1 = `[(1/2, 1/2, 1/2),(1/2, 1/2, -1/2),(-1, 0, 1)]`

Applying R3 → R3 + R2, we get

`[(1, 1, 0),(0, 1, 0),(0, 0, 1)]` A−1 = `[(1/2, 1/2, 1/2),(1/2, 1/2, -1/2),(-1/2, 1/2, 1/2)]`

∴ A−1 = `[(1/2, 1/2, 1/2),(1/2, 1/2, -1/2),(-1/2, 1/2, 1/2)]`

∴ X = `[(1/2, 1/2, 1/2),(1/2, 1/2, -1/2),(-1/2, 1/2, 1/2)] [(1),(5/3),(4/3)]`       .......[From (i)]

∴ `[(x),(y),(z)] = [(1/3),(2/3),(3/1)]`

∴ By equality of matrices, we get

x = `1/3` y = `2/3` and z = 1

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 1.2: Matrics - Long Answers III

संबंधित प्रश्‍न

Let A be a nonsingular square matrix of order 3 × 3. Then |adj A| is equal to ______.


Examine the consistency of the system of equations.

3x − y − 2z = 2

2y − z = −1

3x − 5y = 3


Examine the consistency of the system of equations.

5x − y + 4z = 5

2x + 3y + 5z = 2

5x − 2y + 6z = −1


Solve the system of linear equations using the matrix method.

x − y + 2z = 7

3x + 4y − 5z = −5

2x − y + 3z = 12


Evaluate the following determinant:

\[\begin{vmatrix}\cos 15^\circ & \sin 15^\circ \\ \sin 75^\circ & \cos 75^\circ\end{vmatrix}\]


Show that

\[\begin{vmatrix}\sin 10^\circ & - \cos 10^\circ \\ \sin 80^\circ & \cos 80^\circ\end{vmatrix} = 1\]


Find the value of x, if

\[\begin{vmatrix}2 & 3 \\ 4 & 5\end{vmatrix} = \begin{vmatrix}x & 3 \\ 2x & 5\end{vmatrix}\]


Evaluate the following determinant:

\[\begin{vmatrix}6 & - 3 & 2 \\ 2 & - 1 & 2 \\ - 10 & 5 & 2\end{vmatrix}\]


Without expanding, show that the value of the following determinant is zero:

\[\begin{vmatrix}8 & 2 & 7 \\ 12 & 3 & 5 \\ 16 & 4 & 3\end{vmatrix}\]


\[\begin{vmatrix}- a \left( b^2 + c^2 - a^2 \right) & 2 b^3 & 2 c^3 \\ 2 a^3 & - b \left( c^2 + a^2 - b^2 \right) & 2 c^3 \\ 2 a^3 & 2 b^3 & - c \left( a^2 + b^2 - c^2 \right)\end{vmatrix} = abc \left( a^2 + b^2 + c^2 \right)^3\]


Prove the following identity:

\[\begin{vmatrix}a + x & y & z \\ x & a + y & z \\ x & y & a + z\end{vmatrix} = a^2 \left( a + x + y + z \right)\]

 


Show that

\[\begin{vmatrix}x + 1 & x + 2 & x + a \\ x + 2 & x + 3 & x + b \\ x + 3 & x + 4 & x + c\end{vmatrix} =\text{ 0 where a, b, c are in A . P .}\]

 


Find the area of the triangle with vertice at the point:

 (0, 0), (6, 0) and (4, 3)


Using determinants show that the following points are collinear:

(5, 5), (−5, 1) and (10, 7)


Using determinants show that the following points are collinear:

(1, −1), (2, 1) and (4, 5)


Using determinants show that the following points are collinear:

(3, −2), (8, 8) and (5, 2)


Using determinants show that the following points are collinear:

(2, 3), (−1, −2) and (5, 8)


Find the value of x if the area of ∆ is 35 square cms with vertices (x, 4), (2, −6) and (5, 4).


Using determinants, find the equation of the line joining the points

(3, 1) and (9, 3)


Find values of k, if area of triangle is 4 square units whose vertices are 
(k, 0), (4, 0), (0, 2)


Prove that :

\[\begin{vmatrix}1 & a & bc \\ 1 & b & ca \\ 1 & c & ab\end{vmatrix} = \begin{vmatrix}1 & a & a^2 \\ 1 & b & b^2 \\ 1 & c & c^2\end{vmatrix}\]

 


Prove that :

\[\begin{vmatrix}a^2 & a^2 - \left( b - c \right)^2 & bc \\ b^2 & b^2 - \left( c - a \right)^2 & ca \\ c^2 & c^2 - \left( a - b \right)^2 & ab\end{vmatrix} = \left( a - b \right) \left( b - c \right) \left( c - a \right) \left( a + b + c \right) \left( a^2 + b^2 + c^2 \right)\]

Prove that :

\[\begin{vmatrix}x + 4 & x & x \\ x & x + 4 & x \\ x & x & x + 4\end{vmatrix} = 16 \left( 3x + 4 \right)\]

x − y + 3z = 6
x + 3y − 3z = − 4
5x + 3y + 3z = 10


For what value of x, the following matrix is singular?

\[\begin{bmatrix}5 - x & x + 1 \\ 2 & 4\end{bmatrix}\]

 


If w is an imaginary cube root of unity, find the value of \[\begin{vmatrix}1 & w & w^2 \\ w & w^2 & 1 \\ w^2 & 1 & w\end{vmatrix}\]


If \[A = \left[ a_{ij} \right]\]   is a 3 × 3 diagonal matrix such that a11 = 1, a22 = 2 a33 = 3, then find |A|.

 

Write the value of the determinant \[\begin{vmatrix}2 & - 3 & 5 \\ 4 & - 6 & 10 \\ 6 & - 9 & 15\end{vmatrix} .\]


If \[A = \begin{bmatrix}5 & 3 & 8 \\ 2 & 0 & 1 \\ 1 & 2 & 3\end{bmatrix}\]. Write the cofactor of the element a32.


Let \[\begin{vmatrix}x^2 + 3x & x - 1 & x + 3 \\ x + 1 & - 2x & x - 4 \\ x - 3 & x + 4 & 3x\end{vmatrix} = a x^4 + b x^3 + c x^2 + dx + e\] 
be an identity in x, where abcde are independent of x. Then the value of e is


The maximum value of  \[∆ = \begin{vmatrix}1 & 1 & 1 \\ 1 & 1 + \sin\theta & 1 \\ 1 + \cos\theta & 1 & 1\end{vmatrix}\] is (θ is real)

 





The value of \[\begin{vmatrix}1 & 1 & 1 \\ {}^n C_1 & {}^{n + 2} C_1 & {}^{n + 4} C_1 \\ {}^n C_2 & {}^{n + 2} C_2 & {}^{n + 4} C_2\end{vmatrix}\] is


Show that the following systems of linear equations is consistent and also find their solutions:
2x + 3y = 5
6x + 9y = 15


If \[A = \begin{bmatrix}3 & - 4 & 2 \\ 2 & 3 & 5 \\ 1 & 0 & 1\end{bmatrix}\] , find A−1 and hence solve the following system of equations: 

If \[A = \begin{bmatrix}2 & 3 & 1 \\ 1 & 2 & 2 \\ 3 & 1 & - 1\end{bmatrix}\] , find A–1 and hence solve the system of equations 2x + y – 3z = 13, 3x + 2y + z = 4, x + 2y – z = 8.


A company produces three products every day. Their production on a certain day is 45 tons. It is found that the production of third product exceeds the production of first product by 8 tons while the total production of first and third product is twice the production of second product. Determine the production level of each product using matrix method.


Two institutions decided to award their employees for the three values of resourcefulness, competence and determination in the form of prices at the rate of Rs. xy and z respectively per person. The first institution decided to award respectively 4, 3 and 2 employees with a total price money of Rs. 37000 and the second institution decided to award respectively 5, 3 and 4 employees with a total price money of Rs. 47000. If all the three prices per person together amount to Rs. 12000 then using matrix method find the value of xy and z. What values are described in this equations?


3x − y + 2z = 0
4x + 3y + 3z = 0
5x + 7y + 4z = 0


The system of linear equations:
x + y + z = 2
2x + y − z = 3
3x + 2y + kz = 4 has a unique solution if


Consider the system of equations:
a1x + b1y + c1z = 0
a2x + b2y + c2z = 0
a3x + b3y + c3z = 0,
if \[\begin{vmatrix}a_1 & b_1 & c_1 \\ a_2 & b_2 & c_2 \\ a_3 & b_3 & c_3\end{vmatrix}\]= 0, then the system has


The system of equations:
x + y + z = 5
x + 2y + 3z = 9
x + 3y + λz = µ
has a unique solution, if
(a) λ = 5, µ = 13
(b) λ ≠ 5
(c) λ = 5, µ ≠ 13
(d) µ ≠ 13


x + y = 1
x + z = − 6
x − y − 2z = 3


The value of x, y, z for the following system of equations x + y + z = 6, x − y+ 2z = 5, 2x + y − z = 1 are ______


What is the nature of the given system of equations

`{:(x + 2y = 2),(2x + 3y = 3):}`


Let the system of linear equations x + y + az = 2; 3x + y + z = 4; x + 2z = 1 have a unique solution (x*, y*, z*). If (α, x*), (y*, α) and (x*, –y*) are collinear points, then the sum of absolute values of all possible values of α is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×