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Question
Simplify
sin A `[[sinA -cosA],["cos A" " sinA"]] + cos A[[ cos A" sin A " ],[-sin A" cos A"]]`
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Solution
sin A `[[sinA -cosA],["cos A" " sinA"]] + cos A [[ cos A" sin A " ],[-sin A" cos A"]]`
= ` [[sin^2A " - sin A cos A"],[sinA .cos A - sin^2 A ]]+ [[cos^2 A " cos A . sin A"],[ -sinA cos A cos^2 A]]`
` =[[sin^2 A + cos^2 A " - sin A. cos A + cos A . sin A "],[sin A . cos A - sin A . cos A " sin^2 A + cos^2 A]] = [[ 1 0 ] , [ 0 1]]`
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