O 30 O 12 O 15 27 auct The dot product of two vectors u a i b j and v a i b j is defined as u v a a2 b b For more information on this topic look in your textbook at section 6 7 You might also want to look at the Dot Product presentation Question How much is 3i 2j 7i 3j NOTE Two vectors are orthogonal perpendicular if and only if their dot product is zero