anonymous one year ago find the angle between the vectors a = I^ + 2j^ - k^ and b = -I^ + j^ -2k^

• This Question is Open
1. IrishBoy123

nothing obvious about it so use the dot product: $$\vec a \bullet \vec b = |\vec a||\vec b| cos \theta$$

2. anonymous

can u pls solve it

3. IrishBoy123

can't. site has rules about stuff like that. but i can tell you that, if $$\large \vec a = a_x \hat i + a_y \hat j + a_z \hat k$$ and $$\large \vec b = b_x \hat i + b_y \hat j + b_z \hat k$$, then $$\large \vec a \bullet \vec b = a_xb_x + a_yb_y + a_zb_z$$