math
posted by matematicass .
what angle between vectors u = 2j+2k & v= 3i+4k
Gracias por ayudarme

u.v = u * v * cosθ
cosθ = (6+8)/(2√2)(5) = 14/10√2
θ = 8.13° 
u dot v = u v cos(theta)
u dot v = 6
u = 2 sqrt(2)
v = 5
cos(theta) = 3/[5 sqrt(2)] 
Correction u dot v = 8, so
cos(theta) = 4/[5 sqrt(2)] 
but isn't is a three dimensional vectors

my bad. I misread the problem.
Count Iblis is correct.
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