What is a⋅b\mathbf{a} \cdot \mathbf{b}a⋅b if a=2i+3j\mathbf{a} = 2\mathbf{i} + 3\mathbf{j}a=2i+3j and b=i−j+k\mathbf{b} = \mathbf{i} - \mathbf{j} + \mathbf{k}b=i−j+k?
555
−1-1−1
111
−5-5−5