Use Hagen-Poiseuille Equation to find DP’L1 and DP’L2
L1 dy2
where u’ = 1.5 [1- (y/0.5)2 ]
du’/dy’ = 1.5 ( - 4*2y)
d2u’/dy’2 = - 12
DP’L1 = ( - L1) x ( - 12)
= 3 x 12 = 36