हिंदी

Given A = [22-4-42-42-15], B = [1-10234012], find BA and use this to solve the system of equations y + 2z = 7, x – y = 3, 2x + 3y + 4z = 17.

Advertisements
Advertisements

प्रश्न

Given A = `[(2, 2, -4),(-4, 2, -4),(2, -1, 5)]`, B = `[(1, -1, 0),(2, 3, 4),(0, 1, 2)]`, find BA and use this to solve the system of equations y + 2z = 7, x – y = 3, 2x + 3y + 4z = 17.

योग
Advertisements

उत्तर

We have, A = `[(2, 2, -4),(-4, 2, -4),(2, -1, 5)]` and B = `[(1, -1, 0),(2, 3, 4),(0, 1, 2)]`

∴ BA = `[(1, -1, 0),(2, 3, 4),(0, 1, 2)] [(2, 2, -4),(-4, 2, -4),(2, -1, 5)]`

= `[(6, 0, 0),(0, 6, 0),(0, 0, 6)]`

= 6I

∴ B–1 = `"A"/6 = 1/6 [(2, 2, -4),(-4, 2, -4),(2,  -1, 5)]`  ....(i)

Given system of equation is:

x – y = 3

2x + 3y + 4z = 17

And y + 2z = 7

or `[(1, -1, 0),(2, 3, 4),(0, 1, 2)] [(x),(y),(z)] = [(3),(17),(7)]`

∴ `[(x),(y),(z)] = [(1, -1, 0),(2, 3, 4),(0, 1, 2)]^-1 [(3),(17),(7)]`

= `1/6 [(2, 2, -4),(-4, 2, -4),(2, -1, 5)] [(3),(17),(7)]`

= `1/16 [(6 + 34 - 28),(-12 + 34 - 28),(6 - 17 + 35)]`

= `1/6 [(12),(-6),(24)]`

= `[(2),(-1),(4)]`

∴ x = 2, y = –1 and z = 4

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 4: Determinants - Exercise [पृष्ठ ७९]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 12
अध्याय 4 Determinants
Exercise | Q 20 | पृष्ठ ७९

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

Write Minors and Cofactors of the elements of the following determinant:

`|(2,-4),(0,3)|`


Write Minors and Cofactors of the elements of the following determinant:

`|(1,0,4),(3,5,-1),(0,1,2)|`


Using matrices, solve the following system of equations :

2x - 3y + 5z = 11

3x + 2y - 4z = -5

x + y - 2z = -3


Write the minor and cofactor of element of the first column of the following matrix and hence evaluate the determinant:

\[A = \begin{bmatrix}1 & - 3 & 2 \\ 4 & - 1 & 2 \\ 3 & 5 & 2\end{bmatrix}\]


Write the minor and cofactor of element of the first column of the following matrix and hence evaluate the determinant:

\[A = \begin{bmatrix}1 & a & bc \\ 1 & b & ca \\ 1 & c & ab\end{bmatrix}\]


Write the minor and cofactor of element of the first column of the following matrix and hence evaluate the determinant:

\[A = \begin{bmatrix}a & h & g \\ h & b & f \\ g & f & c\end{bmatrix}\]


Write the minor and cofactor of element of the first column of the following matrix and hence evaluate the determinant:

\[A = \begin{bmatrix}2 & - 1 & 0 & 1 \\ - 3 & 0 & 1 & - 2 \\ 1 & 1 & - 1 & 1 \\ 2 & - 1 & 5 & 0\end{bmatrix}\]


If \[A = \begin{vmatrix}a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ a_{31} & a_{32} & a_{33}\end{vmatrix}\]  and Cij is cofactor of aij in A, then value of |A| is given 




Write the adjoint of the matrix \[A = \begin{bmatrix}- 3 & 4 \\ 7 & - 2\end{bmatrix} .\]


If Cij is the cofactor of the element aij of the matrix \[A = \begin{bmatrix}2 & - 3 & 5 \\ 6 & 0 & 4 \\ 1 & 5 & - 7\end{bmatrix}\], then write the value of a32C32.


Write \[A^{- 1}\text{ for }A = \begin{bmatrix}2 & 5 \\ 1 & 3\end{bmatrix}\]


Find A–1 if A = `[(0, 1, 1),(1, 0, 1),(1, 1, 0)]` and show that A–1 = `("A"^2 - 3"I")/2`.


If A = `[(1, 2, 0),(-2, -1, -2),(0, -1, 1)]`, find A–1. Using A–1, solve the system of linear equations x – 2y = 10, 2x – y – z = 8, –2y + z = 7.


Using matrix method, solve the system of equations
3x + 2y – 2z = 3, x + 2y + 3z = 6, 2x – y + z = 2.


The sum of the products of elements of any row with the co-factors of corresponding elements is equal to ______.


Evaluate the determinant `Delta = abs (("log"_3  512, "log"_4  3),("log"_3  8, "log"_4  9))`


`abs(("cos"  15°, "sin"  15°),("sin"  75°, "cos"  75°))`


After deleting the \(i\)-th row and \(j\)-th column from a square matrix of order \(n\), what is the order of the remaining matrix used to calculate \(M_{ij}\)?


What is the first step to find the minor \(M_{ij}\)?


Which operation is performed immediately after selecting \(a_{ij}\) to find \(M_{ij}\)?


What calculation gives the resulting value \(M_{ij}\) after the required row and column have been deleted?


For \[\begin{vmatrix}1&-2\\4&3\end{vmatrix}\], what is \(M_{11}\)?


For \[\begin{vmatrix}1&-2\\4&3\end{vmatrix}\], what is \(M_{22}\)?


For \[\begin{vmatrix}1&-2\\4&3\end{vmatrix}\], what is \(A_{11}\)?


Which expression gives determinant expansion along row \(i\)?


Which expression gives determinant expansion along column \(j\)?


How does the determinant value change when expansion is performed along a different row or column?


For \(i\ne k\), which mixed row/column property is correct?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×