Following are four different relations about displacement, velocity and acceleration for the motion of a particle in general. Choose the incorrect one (s) :
A. vₐᵥ=r(t₂)−r(t₁)/t₂=t₁
B. vₐᵥ=1/2[v(t₁)+v(t₂)]
C. r=1/2(v(t₂)−v(t₁))(t₂−t₁)
D. aₐᵥ=v(t₂)−v(t₁)/t₂−t₁