Question

Determine whether u=i+2 square root of 5j is orthogonal to v=4square root of 5i -2j.
And just so you know the -2j is not in the square root

Answer 1

if u dot v = 0 then the vectors are orthogonal

Answer 2

Can you show me how to solve it?

Answer 3

do you know the dot product ?

Answer 4

Yeah I know that u dot v is supposed to equal 0 I just don't know how to prove it in this case

Answer 5

u = <1, 2sqrt(5)>
v = <4sqrt(5),-2>

(1)(4sqrt(5) + 2sqrt(5)(-2) = 0 ??

Answer 6

Ohhhh got it thank you (: