हिंदी

If A= [cosα-sinαsinαcosα] then A + A' = I then the value of α is ______. - Mathematics

Advertisements
Advertisements

प्रश्न

If A= `[(cos alpha, -sin alpha), (sin alpha, cos alpha)]` then A + A' = I then the value of α is  ______.

विकल्प

  • `pi/6`

  • `pi/3`

  • `pi`

  •  `(3pi)/2`

MCQ
रिक्त स्थान भरें
Advertisements

उत्तर

If A= `[(cos alpha, -sin alpha), (sin alpha, cos alpha)]` then A + A' = I then the value of α is  `underline(pi/3)`.

Explanation:

`A = [(cos alpha , -sin alpha),(sin  alpha , cos  alpha)], A' = [(cos  alpha , sin  alpha),(-sin  alpha, cos  alpha)]`

`therefore A + A' = I`

`[(cos  alpha, - sin  alpha),(sin  alpha, cos  alpha)] + [(cos  alpha , sin  alpha), (- sin  alpha, cos  alpha)] = [(1,0), (0,1)]`

`=> [(cos  alpha + cos  alpha, -sin  alpha + sin  alpha), (sin  alpha - sin  alpha, cos  alpha + cos  alpha)] = [(1,0),(0,1)]`

`=> [(2  cos  alpha, 0), (0, 2 cos  alpha)] =[(1,0), (0,1)]`

`=> 2  cos  alpha = 1/2`

`=> cos  alpha = cos pi/3`

`therefore alpha = pi/3`

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Matrices - Exercise 3.3 [पृष्ठ ९०]

APPEARS IN

एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
अध्याय 3 Matrices
Exercise 3.3 | Q 12 | पृष्ठ ९०

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

if `2[[3,4],[5,x]]+[[1,y],[0,1]]=[[7,0],[10,5]]` , find (xy).


If `[[x-y,z],[2x-y,w]]=[[-1,4],[0,5]]` find the value of x+y.


Find xya and b if

`[[2x-3y,a-b,3],[1,x+4y,3a+4b]]`=`[[1,-2,3],[1,6,29]]`


Find xy and z so that A = B, where`A= [[x-2,3,2x],[18z,y+2,6x]],``b=[[y,z,6],[6y,x,2y]]`


`If [[x-y,z],[2x-y,w]]=[[-1,4],[0,5]]`Find X,Y,Z,W.


`If [[x + 3 , z + 4 ,     2y-7 ],[4x + 6,a-1,0 ],[b-3,3b,z + 2c ]]= [[0,6,3y-2],[2x,-3,2c-2],[2b + 4,-21,0]]`Obtain the values of abcxy and z.

 


`If [[xy          4],[z+6     x+y ]]``=[[8     w],[0     6]]`, then find the values of X,Y,Z and W . 


Given an example of

a row matrix which is also a column matrix,


For what values of x and y are the following matrices equal?

`A=[[2x+1   2y],[0              y^2 - 5y]]``B=[[x + 3      y^2 +2],[0        -6]]`


Find the values of x and y if

`[[X + 10,Y^2 + 2Y],[0, -4]]`=`[[3x +4,3],[0,y^2-5y]]`


For what values of a and b if A = B, where

`A = [[a + 4        3b],[8        -6]]   B = [[2a +2              b^2+2],[8                    b^2  - 5b]]`

Disclaimer: There is a misprint in the question, b2 − 5should be written instead of b2 − 56.


If  \[\begin{bmatrix}x + 3 & 4 \\ y - 4 & x + y\end{bmatrix} = \begin{bmatrix}5 & 4 \\ 3 & 9\end{bmatrix}\] , find x and y


Find the value of x from the following: `[[2x - y          5],[ 3                         y ]]` = `[[6            5 ],[3         - 2\]]`


Find the value of y, if \[\begin{bmatrix}x - y & 2 \\ x & 5\end{bmatrix} = \begin{bmatrix}2 & 2 \\ 3 & 5\end{bmatrix}\]


If matrix A = [1 2 3], write AAT.


if  \[\begin{bmatrix}2x + y & 3y \\ 0 & 4\end{bmatrix} = \begin{bmatrix}6 & 0 \\ 6 & 4\end{bmatrix}\]  , then find x.


If \[A = \begin{bmatrix}1 & 2 \\ 3 & 4\end{bmatrix}\] , find A + AT.


If \[\begin{bmatrix}a + b & 2 \\ 5 & b\end{bmatrix} = \begin{bmatrix}6 & 5 \\ 2 & 2\end{bmatrix}\] , then find a.


If A = `[[3,1] , [7,5]]`, find the values of x and y such that A2 + xI2 = yA.


If A `= [(0,-1,2),(1,0,3),(-2,-3,0)],` then A + 2AT equals


On her birthday, Seema decided to donate some money to the children of an orphanage home. If there were 8 children less, everyone would have got Rs.10 more. However, if there were 16 children more, everyone would have got Rs. 10 less. Let the number of children be x and the amount distributed by Seema for one child be y(in Rs.).

Based on the information given above, answer the following questions:

  • The equations in terms x and y are ____________.

On her birthday, Seema decided to donate some money to the children of an orphanage home. If there were 8 children less, everyone would have got Rs.10 more. However, if there were 16 children more, everyone would have got Rs. 10 less. Let the number of children be x and the amount distributed by Seema for one child be y(in Rs.).

Based on the information given above, answer the following questions:

  • Which of the following matrix equations represent the information given above?

On her birthday, Seema decided to donate some money to the children of an orphanage home. If there were 8 children less, everyone would have got Rs.10 more. However, if there were 16 children more, everyone would have got Rs. 10 less. Let the number of children be x and the amount distributed by Seema for one child be y(in Rs.)

Based on the information given above, answer the following questions:

  • The number of children who were given some money by Seema, is ____________.

On her birthday, Seema decided to donate some money to the children of an orphanage home. If there were 8 children less, everyone would have got Rs.10 more. However, if there were 16 children more, everyone would have got Rs. 10 less. Let the number of children be x and the amount distributed by Seema for one child be y(in Rs.)

Based on the information given above, answer the following questions:

  • How much amount Seema spends in distributing the money to all the students of the Orphanage?

Two matrices A = [aÿ] and B = [bÿ] are said to be equal if.


If A = `[(cos a, - sin a),(sin a, cos a)]`, then A+ A1 = l, if the value of a is:


Choose the correct answer in the following questions

If A = `[(alpha, beta),(y, - a)]` is such that A2 = I, then


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×