Question

prove that the resultant of two vectors of equal magnitude are equal to either vector if the angle is between the two vectors is 120​

Answer 1

Answer:

let a and b be the 2 vectors

a=b= c (let)

cos120= - 1/2

resultant= $\sqrt{a^{2} +b^{2}+2abcos120 }$

              = $\sqrt{c^{2} +c^{2}-c^{2} }$

              = c = a = b

                         proved