Question

( A=left[begin{array}{ll}cos 2 theta & sin 2 theta -sin 2 theta & cos 2 thetaend{array}right] )
( A^{2}=left[begin{array}{cc}cos 2 theta & sin 2 theta -sin 2 theta & cos 2 thetaend{array}right]left[begin{array}{cc}cos 2 theta & sin 2 theta -sin 2 theta & cos 2 thetaend{array}right] )
( A^{2}=left[begin{array}{cc}cos 4 theta & sin 4 theta -sin 4 theta & cos 4 thetaend{array}right] )
( A^{2} cdot A=left[begin{array}{cc}cos 4 theta & sin 4 theta -sin theta theta & cos 4 thetaend{array}right]left[begin{array}{cc}cos 2 theta & sin 2 theta sin 2 theta & cos 2 thetaend{array}right] )
( A^{3}=left[begin{array}{cc}cos 6 theta & sin 6 theta -sin theta theta & cos 6 thetaend{array}right] )

# b c (532 If A = cos 20 1-sin 20 La sin 201 cos 2 el then find A. 11-11 11

Solution