Question

AB^2=a^2+a^2+a.a/2 show that AB=√3.a

Answer 1

In AB^2=a^2+a^2+(a*a)/2
R.H.S.=a^2+a^2+(a^2)/2
          =>{2*(a^2)+2*(a^2)+a^2}/2          [taking the L.C.M. i.e. 2]
          =>(5a^2)/2 or 2.5a^2