<Dl> <Dd> a ⋅ b = b ⋅ a, (\ displaystyle \ mathbf (a) \ cdot \ mathbf (b) = \ mathbf (b) \ cdot \ mathbf (a),) </Dd> <Dd> which follows from the definition (θ is the angle between a and b): </Dd> <Dd> a ⋅ b = ∥ a ∥ ∥ b ∥ cos ⁡ θ = ∥ b ∥ ∥ a ∥ cos ⁡ θ = b ⋅ a . (\ displaystyle \ mathbf (a) \ cdot \ mathbf (b) = \ left \ \ mathbf (a) \ right \ \ left \ \ mathbf (b) \ right \ \ cos \ theta = \ left \ \ mathbf (b) \ right \ \ left \ \ mathbf (a) \ right \ \ cos \ theta = \ mathbf (b) \ cdot \ mathbf (a).) </Dd> </Dl> <Dd> a ⋅ b = b ⋅ a, (\ displaystyle \ mathbf (a) \ cdot \ mathbf (b) = \ mathbf (b) \ cdot \ mathbf (a),) </Dd> <Dd> which follows from the definition (θ is the angle between a and b): </Dd> <Dd> a ⋅ b = ∥ a ∥ ∥ b ∥ cos ⁡ θ = ∥ b ∥ ∥ a ∥ cos ⁡ θ = b ⋅ a . (\ displaystyle \ mathbf (a) \ cdot \ mathbf (b) = \ left \ \ mathbf (a) \ right \ \ left \ \ mathbf (b) \ right \ \ cos \ theta = \ left \ \ mathbf (b) \ right \ \ left \ \ mathbf (a) \ right \ \ cos \ theta = \ mathbf (b) \ cdot \ mathbf (a).) </Dd>

Can you dot a scalar with a vector