heh, yeah i did square it wrong that time... but on my paper i did it just like that, but after i use the quadratic formula on the final outcome, its still wrong... maybe you have better luck?
Well its not so much the quadratic that troubles me, as the solution. When i solve it i get a number with decimals, and it is not near the final answer which the book gives. (4)
If someone could finish off my solution that would be great, as when i did it, it was incorrect.
Homework Statement
The cosine of the angle between vector a and vector b is 4/21. Find p.
vector a = 6i + 3j - 2k
vector b = -2i + pj - 4k
Homework Equations
(Vector a) . (Vector b) = abcos(theta)
(Vector a) . (Vector b) = axbx + ayby + azbz
mag(a) = root(ax^2 + ay^2 + az^2)
The Attempt at...