Answer :

We are given that,

is an identity matrix.

We need to find the value of α.

We must understand what an identity matrix is.

An identity matrix is a square matrix in which all the elements of the principal diagonal are ones and all other elements are zeroes.

An identity matrix is denoted by

According to the question,

We know by the property of matrices,

This implies,

a11 = b11, a12 = b12, a21 = b21 and a22 = b22

So, if we have

The corresponding elements of matrices are equal.

That is,

cos α = 1

-sin α = 0

sin α = 0

cos α = 1

Since, the equations are repetitive, take

cos α = 1

α = cos-1 1

α = 0°

Thus, the value of α = 0°.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses

Using matrices, sMathematics - Board Papers

If possible, usinMathematics - Exemplar

If possible, usinMathematics - Exemplar

Using matrices, sMathematics - Board Papers

Prove that <span Mathematics - Board Papers

Find the value ofMathematics - Board Papers

If A is a <span lMathematics - Board Papers