1. Evaluate L (4-6x) dx two different ways. -2 (a) By (only) Riemann definition of the definite integral with: i. 2 = i; ii. x = xi-1. (b) "Geometrically", i.e. sketch and shade in the signed area described by this integral and find the area of this shaded region by interpret- ing it as a sum of areas of simple geometric shapes.