If a and b are position vectors, which one of the following is the clear property of the scalar product of two vectors a and b.
\( a.b=|a||b| sinθ\)
\( a.b=(a+b)(a-b)cosθ\)
\( a.b=|a||b| cosθ\)
\( a.b=(a+b)(a-b)\)
