anonymous one year ago SIMPLE MATRIX QUESTION PLEASE HELP!! are the given vectors normal? a = (5,-2) and b = (6,15)

1. anonymous

@GEERKY42

2. anonymous

@sithsandgiggles

3. anonymous

@jagr2713

4. anonymous

@freckles

5. anonymous

@whpalmer4

6. anonymous

@greg_d

7. anonymous

is the question asking if they are perpendicular to each other?

8. anonymous

@greg_d all it is asking is if it is "normal"

9. anonymous

I can't determine what or why or how it would be considered normal.. the rest of the homework was working on matrices

10. anonymous

if the question is, are they "normal" (as perpendicular) to each other, you can use the dot product...

11. anonymous

This is honestly the last problem and i don't know how i could do that..

12. anonymous

@greg_d

13. anonymous

ok, IF that is the question, we need to multiply them using the dot product. $a.b=a_xb_x+a_yb_y$ since$a.b=|a||b|cos(\theta)$ with theta beign the angle between the vectors. if that product is 0, said angle is 90º and they are indeed "normal" to each other

14. anonymous

could you possibly solve that for me so i can use it next time i see something like this?

15. anonymous

@greg_d

16. jim_thompson5910

Similar Example: Let's say you had the two vectors u = <1,2> v = <5,7> The dot product of u and v is u dot v = 1*5 + 2*7 = 5 + 14 = 19 Since the dot product is not 0, this means that u and v are not perpendicular

17. jim_thompson5910

In general u = <a,b> v = <c,d> u dot v = a*c + b*d u,v are vectors a,b,c,d are scalars

18. anonymous

@jim_thompson5910 @greg_d Thank you!!

19. anonymous

:D that examples will lead you to the answer !