Derive Eq. 5-20 from Eqs. 5-18 and 5-19. In Eq. 5-20 = i t +

Derive Eq. 5-20 from Eqs. 5-18 and 5-19.
In Eq. 5-20
∆ω = ωi ∆t + ½ α (∆t)2
In Eq. 5-18
∆ω = ωf - ωi = α∆t
In Eq. 5-19
∆θ = 1/2(ωf + ωi) ∆t