PLEASE HELP Evaluate the expression: v ⋅ w Given the vectors: r = ; v = ; w =

Question

PLEASE HELP Evaluate the expression: v ⋅ w Given the vectors: r = <5, -5, -2>; v = <2, -8, -8>; w = <-2, 6, -5>

imqwerty · Answer

-12 :)

anonymous · Answer

how did you get that? @imqwerty

imqwerty · Answer

we need to find v.w 
we have-
v=2i-8j-8k
j=-2i+6j-5k

for any 2 vectors a,b   
a.b= (product of their component along i)+(product of their component along j)+(product of their component along  k)

so v.j=(2x -2)+(-8x6)+(-8x -5)
         =-12

anonymous · Answer

ohh okay thank you so much, could you help me with one other question

imqwerty · Answer

ok

anonymous · Answer

Find a ⋅ b. a = <7, 4>, b = <3, 5>

imqwerty · Answer

have u tried solving this problem??

imqwerty · Answer

41

anonymous · Answer

i got 21,20

imqwerty · Answer

well a=7i+4j
       b=3i+5j
a.b=(7x3)+(4x5)
      =21+20
      =41