Review Videos Videos, Math Dr. Bob: Trig sub 1: Basics and ∫136−x2dx and ∫x36+x2dx and ∫1x2−36dx Trig sub 2: ∫dx(1+x2)5/2 Trig sub 3: ∫x21−4x2dx Trig sub 4: ∫e2x−1dx Trig sub 5: ∫4−36x2x2dx