Given two vectors a⃗ = 4.60 i^+ 7.20 j^ and b⃗ = 5.10 i^− 2.70 j^ , find the scalar product of the two vectors a⃗ and b⃗ .

a=<4.60,7.20>
b=<5.10,2.70>
The scalar product, or the inner product, or the dot-product, is by summing the products of the respective directions, 
a.b=4.6*5.1+7.2*2.7
=23.46+19.44
=42.9