- #1
noeinstein
- 14
- 0
Use the definition of scalar product, a·b = ab cos , and the fact that a·b = axbx + ayby + azbz (see Problem 46) to calculate the angle between the two vectors given by a = 2.0 i + 6.0 j + 2.0 k and b = 4.0 i + 3.0 j + 6.0 k.
AdotB= 8i + 18j + 12k
A=sqrt(2^2 + 6^2 + 2^2)=6.63
B=sqrt(4^2 + 3^2 + 6^2)=7.81
AdotB=(6.63)(7.81)cosΘ
Θ=acos(38/51.78)
Θ=42.79=WRONG
AdotB= 8i + 18j + 12k
A=sqrt(2^2 + 6^2 + 2^2)=6.63
B=sqrt(4^2 + 3^2 + 6^2)=7.81
AdotB=(6.63)(7.81)cosΘ
Θ=acos(38/51.78)
Θ=42.79=WRONG