हिंदी

If A = [(0, –tan  α/2), (tan  α/2, 0)] and I is the identity matrix of order 2, show that I + A = (I – A)[(cos α, –sin α),(sin α, cos α)]

Advertisements
Advertisements

प्रश्न

If A = `[(0, -tan  α/2), (tan  α/2, 0)]` and I is the identity matrix of order 2, show that I + A = `(I - A)[(cos α, -sin α),(sin α, cos α)]`

योग
Advertisements

उत्तर

A = `[(0, -tan  α/2), (tan  α/2, 0)]`, I = `[(1, 0),(0, 1)]` 

I + A = `[(1, 0),(0, 1)] + [(0, -tan  α/2), (tan  α/2, 0)]`

= `[(1, -tan  α/2), (tan  α/2, 1)]`

`(I - A) [(cos α, -sin α),(sin α, cos α)] = ([(1, 0),(0, 1)] - [(0, -tan α/2), (tan α/2, 0)]) [(cos α, -sin α),(sin α, cos α)]`

= `[(1, tan  α/2), (-tan  α/2, 1)] [(cos α, -sin α),(sin α, cos α)]` 

= `[(1, tan  α/2), (-tan  α/2, 1)]` `[((1 - tan^2  α/2)/(1 + tan^2  α/2)(-2  tan  α/2)/(1 + tan^2  α/2)),((-2 tan  α/2)/(1 + tan^2  α/2)(1 - tan^2  α/2)/(1 + tan^2  α/2))]`

= `[((1 + tan^2  α/2)/(1 + tan^2  α/2)(-tan  α/2 - tan^3  α/2)/(1 + tan^2  α/2)),((tan  α/2 + tan^3  α/2)/(1 + tan^2  α/2)(1 + tan^2  α/2)/(1 + tan^2  α/2))]`

= `[(1, -tan  α/2),(tan  α/2, 1)]`

Hence, `I + A = (I - A) [(cos α, -sin α),(sin α, cos α)]`

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Matrices - EXERCISE 3.2 [पृष्ठ ६०]

APPEARS IN

एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
अध्याय 3 Matrices
EXERCISE 3.2 | Q 18. | पृष्ठ ६०

वीडियो ट्यूटोरियलVIEW ALL [2]

संबंधित प्रश्न

If A is a square matrix, such that A2=A, then write the value of 7A(I+A)3, where I is an identity matrix.


Find the value of x, y and z from the following equation:

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


if `A = [(3,-4),(1,-1)]` then prove A"=` [(1+2n, -4n),(n, 1-2n)]` where n is any positive integer


If A and B are square matrices of the same order such that AB = BA, then prove by induction that AB" = B"A. Further, prove that (AB)" = A"B" for all n ∈ N


If A = `[(α, β),(γ, -α)]` is such that A2 = I, then ______.


If A is a square matrix such that A2 = A, then (I + A)3 – 7A is equal to ______.


if the matrix A =`[(0,a,-3),(2,0,-1),(b,1,0)]` is skew symmetric, Find the value of 'a' and 'b'


A coaching institute of English (subject) conducts classes in two batches I and II and fees for rich and poor children are different. In batch I, it has 20 poor and 5 rich children and total monthly collection is Rs 9,000, whereas in batch II, it has 5 poor and 25 rich children and total monthly collection is Rs 26,000. Using matrix method, find monthly fees paid by each child of two types. What values the coaching institute is inculcating in the society?


Investigate for what values of λ and μ the equations
2x + 3y + 5z = 9
7x + 3y - 2z = 8
2x + 3y + λz = μ have
A. No solutions
B. Unique solutions
C. An infinite number of solutions.


Choose the correct alternative.

The matrix `[(8, 0, 0),(0, 8, 0),(0, 0, 8)]` is _______


Classify the following matrix as, a row, a column, a square, a diagonal, a scalar, a unit, an upper triangular, a lower triangular, a symmetric or a skew-symmetric matrix:

`[(0, 0, 1),(0, 1, 0),(1, 0, 0)]`


Identify the following matrix is singular or non-singular?

`[(5, 0, 5),(1, 99, 100),(6, 99, 105)]`


Identify the following matrix is singular or non-singular?

`[(3, 5, 7),(-2, 1, 4),(3, 2, 5)]`


The following matrix, using its transpose state whether it is symmetric, skew-symmetric, or neither:

`[(1, 2, -5),(2, -3, 4),(-5, 4, 9)]`


Construct the matrix A = [aij]3 × 3 where aij = i − j. State whether A is symmetric or skew-symmetric.


Select the correct option from the given alternatives:

If A and B are square matrices of equal order, then which one is correct among the following?


Answer the following question:

If A = diag [2 –3 –5], B = diag [4 –6 –3] and C = diag [–3 4 1] then find B + C – A


If A = `[(6, 0),("p", "q")]` is a scalar matrix, then the values of p and q are ______ respectively.


State whether the following statement is True or False:

If A and B are two square matrices such that AB = BA, then (A – B)2 = A2 – 2AB + B2 


If A = `[(3, 1),(-1, 2)]`, then prove that A2 – 5A + 7I = O, where I is unit matrix of order 2


If A = `[(1, 3, 3),(3, 1, 3),(3, 3, 1)]`, then show that A2 – 5A is a scalar matrix


The matrix A = `[(0, 0, 5),(0, 5, 0),(5, 0, 0)]` is a ______.


For the non singular matrix A, (A′)–1 = (A–1)′.


If A = `[(3, -4),(1, 1),(2, 0)]` and B = `[(2, 1, 2),(1, 2, 4)]`, then verify (BA)2 ≠ B2A2 


Given A = `[(2, 4, 0),(3, 9, 6)]` and B = `[(1, 4),(2, 8),(1, 3)]` is (AB)′ = B′A′? 


If X and Y are 2 × 2 matrices, then solve the following matrix equations for X and Y.

2X + 3Y = `[(2, 3),(4, 0)]`, 3Y + 2Y = `[(-2, 2),(1, -5)]`


`root(3)(4663) + 349` = ? ÷ 21.003


A square matrix B = [bÿ] m × m is said to be a diagonal matrix if all diagonal elements are


A diagonal matrix is said to be a scalar matrix if its diagonal elements are


A square matrix in which elements in the diagonal are all 1 and rest are all zero is called an


A = `[a_(ij)]_(m xx n)` is a square matrix, if


Let A be a 2 × 2 real matrix with entries from {0, 1} and |A| ≠ 0. Consider the following two statements:

(P) If A1I2, then |A| = –1

(Q) If |A| = 1, then tr(A) = 2,

where I2 denotes 2 × 2 identity matrix and tr(A) denotes the sum of the diagonal entries of A. Then ______.


How many matrices can be obtained by using one or more numbers from four given numbers?


If `A = [(1,-1,2),(0,-1,3)], B = [(-2,1),(3,-1),(0,2)],` then AB is a singular matrix.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×