Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Problem
Problem
If
∣
A
∣
=
∣
B
∣
=
A
|\mathbf{A}| = |\mathbf{B}| = A
∣
A
∣
=
∣
B
∣
=
A
(say) then,
∣
R
∣
=
∣
A
+
B
∣
=
2
A
cos
θ
2
|\mathbf{R}| = |\mathbf{A} + \mathbf{B}| = 2A \cos \frac{\theta}{2}
∣
R
∣
=
∣
A
+
B
∣
=
2
A
cos
2
θ
Prove the above result.
Browse the problem library