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If A=[(cos2theta,sin2theta),(-sin2theta,...

If `A=[(cos2theta,sin2theta),(-sin2theta,cos2theta)]` , find `A^2` .

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Given ,
`A=[(cos2theta,sin2theta),(-sin2theta,cos2theta)]`
`A^2=[(cos2theta,sin2theta),(-sin2theta,cos2theta)]xx[(cos2theta,sin2theta),(-sin2theta,cos2theta)]`
`=[(cos^2(2theta)+sin^2(2theta),-cos2theta sin 2theta+cos2theta sin 2theta),(-sin 2thetacos2theta+sin 2thetacos2theta,cos^2(2theta)+sin^2(2theta))]`
`=[(1,0),(0,1)]`
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