## anonymous one year ago **Will give medals, super easy question** Find the vector https://gyazo.com/40f9a92a31ece57307589d029648e4ea

1. jim_thompson5910

have you learned about vector cross products?

2. anonymous

yes

3. jim_thompson5910

how far did you get when you tried out the problem? or were you stuck on how to get started?

4. anonymous

is it just the cross product?..

5. jim_thompson5910

yes you apply the cross product of the two vectors

6. jim_thompson5910

did you need help computing the cross product?

7. anonymous

yes, how do i set this up

8. jim_thompson5910

step 1) write out i,j,k along a horizontal row like this |dw:1444614782773:dw|

9. jim_thompson5910

step 2) write each vector under the i,j,k (line up the corresponding elements) |dw:1444614829596:dw|

10. jim_thompson5910

we will apply the determinant of this matrix |dw:1444614875046:dw| denoted by the vertical bars

11. jim_thompson5910

to apply the determinant, copy the first two columns and move them to the right of the matrix |dw:1444614908976:dw|

12. jim_thompson5910

|dw:1444614942077:dw|

13. jim_thompson5910

now we circle the diagonal elements like so |dw:1444614990848:dw|

14. jim_thompson5910

|dw:1444615040842:dw|

15. jim_thompson5910

add up the results -14i + 2j + 6k

16. jim_thompson5910

now we circle these diagonals |dw:1444615117544:dw|

17. jim_thompson5910

Multiply out the elements in each subgroup |dw:1444615147629:dw|

18. jim_thompson5910

add up the results 7k+(-6i)+4j = -6i+4j+7k

19. jim_thompson5910

the last step is to subtract the two sums (first sum) - (second sum) = (-14i+2j+6k) - (-6i+4j+7k) (first sum) - (second sum) = -14i+2j+6k + 6i - 4j - 7k (first sum) - (second sum) = -8i - 2j - 1k So the cross product of the two vectors is <-8, -2, -1>

20. anonymous

damn, thank you so much, can you help me with one more question though?

21. jim_thompson5910