Question

If three vector a,b, c are mutually perpendicular then which is correct expression?

a x b x c
a.b=a.c
a+(b+c)
axb+axc

Answer 1

Answer:

1)The three vectors are unit vectors i.e; having a length or magnitude equal to 1.

2)They are perpendicular to each other.

So, Consider a reference point where they intersect with each other. Then the components of each and every vector, in the direction of the others don't exist because these vectors themselves form the axes of the coordinates system we have chosen.

So if you form a new vector using these three vectors, it has these three vectors as its components with unit magnitudes.

So, according to vector algebra, |a+b+c| represents the square root of the sum of squares of magnitudes of the components of the vector i.e;

√( 1^2 + 1^2 + 1^2) = √3.