By providing us with a nifty way of finding a vector perpendicular to two given ones, the cross product is ideally suited to finding normals (i.e. perpendicular vectors) to planes.

i) The plane in three-dimensional space spanned by the vectors (1,1,3) and (6,2,4) will have normal vector n= ____________. Remember that such a normal vector n is only determined up to a constant multiple.

ii) The parallelogram with adjacent sides AB and AC, where A=[1,4,3] , B=[4,2,5] and C=[6,4,3] has normal vector ________________ and area equal to _____________ .