Two vectors are given by a = 9.1i + 1.1j and b = 4.9i + 3.8j. Find (a)|a × b|, (b)a · b, (c)(a + b) · b, and (d) the component of a along the direction of b?
What exactly are you having trouble with?
(a) The cross product is only defined for 3-dimensional Euclidean space. So unless you assume the unit vector k to be 0, you can't perform this operation.
(b) . Just plug it in.
(d) The orthogonal projection of a along b is given by: