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Gramsci
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Homework Statement
Find a matrix that diagonalizes the following 2x2 matrix:
A= (1/2 , sqrt(3)/2
sqrt(3)/2,-1/2)
What will the diagonalizing matrix D be? What does D mean geometrically? What does A mean geometrically?
Homework Equations
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The Attempt at a Solution
First I began with computing the characteristic equations determinant:
det A-lambda(call it x)= (1/2-x)(-1/2-x)-(sqrt3/2)(sqrt3/2)=X^2=-1
and since we haven't begun with complex eigenvalues yet:
x(x)=-1
Thus, x1=1 and x2=-1
Then I'm trying to compute the eigenvectors, but I seem to fail after I've added -1 I get:
3/2 , sqrt(3)/2
sqrt(3)/2, 1/2
after row reduction:
3, sqrt(3)
0, 0
Therefore, the eigenvector for -1 have to be (sqrt(3),3)
But according to my solutions manual, it is : 1, - sqrt 3
How do I count for the second one? All these square roots confuse me, any tips on how I handle them in row reduction?
/Gramsci