Question

If A vector = B vector +C vector and magnitudes of A B and C vectors are 5,4,3 units the angle between A vector and C vector ??

Answer 1

Given

A vector =B vector +C vector

and

A=5 B=4 C=3

then

B vector = A vector - C vector

we know

B ^2=A^2 +C^2 -2ACcos theta

theta = cos inverse 3/5