Find the angle between the vectors. (first find an exact expression and then approximate to the nearest degree.)a = 5, −1, 6, b = −2, 6, 3

the points given in  the question is [5,-1,6] and [-2,6,3]

the position vectors associated with these points are  given as

a=5i^-j^+6k^,b= -2i^+6j^+3k^

the dot product of these vectors are given as -

where α is the angle between them .

hence we have cosα=

here

and

hence a= and b=

hence cosα=

                   =5×[-2]+[-1]×6+6×3

                   =

                   =0.0362857507

hence α=2.07947 degree

its c i just checked it