Simplify: cosθ[cosθsinθ−sinθcosθ]+sinθ[sinθ−cosθcosθsinθ]

cosθ[cosθsinθ−sinθcosθ]+sinθ[sinθ−cosθcosθsinθ]
A matrix when multiplied by a constant, gets multiplied to each term of that matrix.
∴[cos²θcosθsinθ−sinθcosθcos²θ]+[sin²θ−sinθcosθcosθsinθsin²θ]=[cos²θ+sin²θcosθsinθ−cosθsinθ−cosθsinθ+cosθsinθcos²θ+sin²θ]=[1001]