Mathematics FROM 3

Two or more vectors are equal if they have the same magnitude, direction and sense.

NB: If one the three properties do not hold, then the vectors are not equal.

Example: Given a vector a=2-1 anb b=-21. State whether they are equal or not.

Solution

a=2-1 b=-21

Magnitude, a=x2+y2

a=22+(-1)²=4+1=5

a=5 units

b=-22+12=4+1=5

b=5 units

Direction

For a

θ=tan-1(yx), Þθ=tan-1-12=-63.40°

For b

θ=tan-1(yx), Þθ=tan-11-2=63.43°

\They are not equal since their senses are different.

par Claude Foumtum

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