Question

find the scalar prpduct of the vector (3,-2,6) and (6,9,2) also find angle between the vectors​

Answer 1

the vectors are a=3i-2j+6k & b=6i+9j+2k

Therefore, |a|=7 & |b|=11

There scalar product will be,

a.b = (3i-2j+6k)(6i+9j+2k)

a.b = 18-18+12 = 12

cos∅ = $\frac{a.b}{|a|.|b|}$

cos∅ = $\frac{12}{7×11}$

cos∅ = $\frac{12}{77}$

Therefore, ∅=cos^-1$\frac{12}{77}$