Question

Given vector a=(2,1,0)and vector b=(-1,0,3) and vector c=(4,-1,1), calculate the following triple scalar and triple vector products.

1. c x a dot b
What I did:
c x a = ((-1)(0)-(1)(1), (1)(2)-(4)(0), (-1)(2)-(4)(1)
=(-1, 2, -6)
(cxa) dot b =(-1,2,-6) dot (-1,0,3)
=(-1)(-1)+(2)(0)+(-6)(3)
=-17

Correct answer:19

2.(cxa)xb
cxa=(-1,2,-6)
=(2)(3)-((-6)(0),(-6)(-1)-(-1)(3),(-1)(0)-(2)(-1)
=(6,9,2)

correct answer is (6,-3,2)

For each question, what did I do wrong because I got the 6 and 2 right in the 2nd and for the 1st, I'm completely wrong.

Answer 1

1.
I got (-1,2,6)
Your error is in the last calculation, I had 4(1) - (2(-1) = 6
and then (-1,2,6)dot((-1,0,3)
= 1 + 0 + 18 = 19

2. since this problem depends on your answer from #1,
check your calculations with the correct answer from #1,
I did get (6,-3,2)