State and proove bernauli theorum?

Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. Derivation :  Let the velocity, pressure and area of a fluid column at a point A be v₁, p and A₂ and at another point B be v₂, p₂, p₂ and A₂ . Let the volume that is bounded by A and B be moved to M and N . let AM = L₁ and BN = L₂ . Now if we can compress the fluid then we have, A₁L₁ = A₂L₂ Net work done per volume = p₂ - p₁ Kinetic energy per volume = 1/2 ρ v² Kinetic energy gained per volume = 1/2 ρ (v₂² - v₁²)  Potential energy gained per volume = ρ g(h₂ - h₁)  Now ,  p₁ - p₂ = 1/2 ρ (v₂² - v₁²)  + ρ g(h₂ - h₁)  p₁ - p₂ = 1/2 ρ v₂² - 1/2 ρ v₁² + ρ g h₂ - ρ g h₁ p₁ +  1/2 ρ v₁²  + ρ g h₁ = p₂ + 1/2 ρ v₂² + ρ g h₂ p + 1/2 ρ v + ρ g h = constant  Hope you like it..