Let vector a={1,1,1} and b={2,-1,-1} the angle between two vectors is

The answer will probabily be "undfined" or "error"

Step-by-step explanation: firtst u need to find the dot product of both a and  b (a.b).

then the magnitude of both (√a ,√b)

then u substitute them into the equation

∅=cos-1(a.b/√a x √b)

u will find it to be error bcoz  it will be (0/√3 x 0)

answer: do you still need this?

sorry, i can't understand your question. will later if you describe more clearly!

: )