Question

plz ans fast...................​

Answer 1

Answer:

2 cos^-1(3A/2)

Explanation:

we know that the magnitude of the resultant of the two vectors say A and B us given by the expression:

R=√(A²+B²+2AB cos θ)

now,here it is given that two vectors are equal.

so,the expression shortens to

R=√(2A²+2A²cos θ)

R=√2A²(1+cos θ)

R=√(2A²*2cos θ/2) ....[1+cos 2θ=2 cos²θ]

R=2Acos(θ/2)

now, further is Given that the magnitude of the resultant is 3 times the product.

=>3A²=2Acos(θ/2)

=>A(3A-2cos(θ/2))=0

Now,A≠0 (as it is not a null vector)

=>3A-2cos(θ/2)=0

=>2cos(θ/2)=3A

=>θ/2= cos^-1(3A/2) ..... (read as cos inverse 3A)

=>θ=2 cos^-1(3A/2)

where 0≤A<2/3

Some additional information:

★Vectors are those physical quantities that requires both magnitude and direction for its complete understanding and it should necessarily follow vector Algebra.

e.g:Force, velocity etc.

★Vectors are very much required for understanding physics

Answer 2

Answer:

plz take a clear pic.....