5. a. Show that, when we consider taxes, the general relationship between operating cash flow, OCE, and sales volume can be written as; OCF-tD FC+ e- PTU where Q is sales volume, EC is the fixed costs, t is tax rate, D is depreciation, p is unit price of the product, and v is the unit variable costs. b. Show that if we consider the effect of taxes, the degree of operating leverage can be written as