||'''Book'''|| Linear Algebra ||
 ||'''Author'''|| Gilbert Strang ||
 ||'''Edition'''||  ||

/* code_begins */

{{{
v = vector([2,1])
w = vector([1,2])
x = sqrt(2*2+1*1)
y = sqrt(1*1+2*2)
cos(theta) = v*w /(x*y)
print cos(theta)
}}}

/* code_ends */

 * '''Solution by''': 
   Siva Jyoshna Poreddy, Student, IIIT-Hyderabad