I have this problem:
d,e,f are vectors in R3
I don't need to hear the solution, I just need some pointers about where to start. I mean, I did the cross multiplication and now I have letters everywhere.
Is there a cross product rule I'm missing? or a dot product rule?
my book and wikipedia say otherwise.
Oh wait, I see it. I go: 23, 31, 12. You go: 23, 13, 12.This equation is the sum of nine simple cross products. After all the multiplication is carried out using the basic cross product relationships between i, j, and k defined above,
a × b = a1b1(0) + a1b2(k) + a1b3(−j) + a2b1(−k) + a2b2(0) + a2b3(i) + a3b1(j) + a3b2(−i) + a3b3(0).
This equation can be factored to form
a × b = (a2b3 − a3b2) i + (a3b1 − a1b3) j + (a1b2 − a2b1) k = (a2b3 − a3b2, a3b1 − a1b3, a1b2 − a2b1).