Question

What is the cross product of `(2i -3j + 4k)` and `(- 5 i + 4 j - 5 k)`?

Answer 1

I found: `-i-10j-7k`

Explanation:

Calling the two vectors `vecu and vecv` we can use the definition of Cross Product to get:
`vecuxxvecv=|(i,j,k),(u_x,u_y,u_z),(v_x,v_y,v_z)|=|(i,j,k),(2,-3,4),(-5,4,-5)|=` evaluating the Determinant:

`vecuxxvecv==-i-10j-7k`