Solution

def taxRevenue(demandEquation,supplyEquation,priceStart,priceEnd,tax):
    equilibriumQ = eqSolve(demandEquation,supplyEquation,tax)
    return tax*equilibriumQ
taxs = []
moneyRaised = []
for x in range(0,11):
    taxs+=[x]
    moneyRaised+=[taxRevenue(10-p,p,0,10,x)]
plt.plot(taxs,moneyRaised)
plt.xlabel("Tax Applied")
plt.ylabel("Money Raised")
plt.title("The Laffer Cuve")
plt.show()

Let’s also make one final modification to our function. We don’t actually need to input the end price ourself, we can just solve for where quantity demanded is equal to 0. So the final form of our function is this:

def EquilibriumTax(demandEquation,supplyEquation,priceStart,tax):
    priceEnd = sympy.solve(demandEquation)[0]
    prices = []
    demand = []
    supply = []
    for price in range(priceStart,priceEnd+1):
        prices += [price]
        demand += [demandEquation.subs(p,price)]
        supply += [supplyEquation.subs(p,price)]



    nonTaxPrice = sympy.solve(demandEquation-supplyEquation)[0]
    nonTaxQ = demandEquation.subs(p,nonTaxPrice)


    equilibriumQ = eqSolve(demandEquation,supplyEquation,tax)
    equilibriumP1 = sympy.solve(demandEquation-equilibriumQ)[0]
    equilibriumP2 = sympy.solve(supplyEquation-equilibriumQ)[0]

    triangle1 = patches.Polygon([[nonTaxQ,nonTaxPrice],[equilibriumQ,nonTaxPrice],[equilibriumQ,equilibriumP1]],True,color="green")
    triangle2 = patches.Polygon([[nonTaxQ,nonTaxPrice],[equilibriumQ,nonTaxPrice],[equilibriumQ,equilibriumP2]],True)
    currentAxis = plt.gca()
    currentAxis.add_patch(triangle1)
    currentAxis.add_patch(triangle2)


    rect1 = patches.Rectangle((0,nonTaxPrice),equilibriumQ,equilibriumP1-nonTaxPrice,linewidth=1,facecolor="red")
    rect2 = patches.Rectangle((0,nonTaxPrice),equilibriumQ,equilibriumP2-nonTaxPrice,linewidth=1,facecolor="yellow")
    currentAxis.add_patch(rect1)
    currentAxis.add_patch(rect2)

    plt.plot(demand,prices)
    plt.plot(supply,prices)


    plt.legend([rect1,rect2,triangle1,triangle2], ["Consumer Tax","Producer Tax","Consumer Deadweight Loss","Producer Deadweight Loss"])
    plt.plot(equilibriumQ,equilibriumP1, 'ro')
    plt.plot(equilibriumQ,equilibriumP2, 'ro')
    plt.xlabel("Supply and Demand Quantity")
    plt.ylabel("Price")
    plt.show()
    print("The equilibrium prices are "+str(equilibriumP1)+" and "+str(equilibriumP2)+" and equilibrium quantity is "+str(equilibriumQ)+".")
    print("Taxes raised from consumers equals "+str(equilibriumQ*(equilibriumP1-nonTaxPrice)))
    print("Taxes raised from producers equals "+str(equilibriumQ*(nonTaxPrice-equilibriumP2)))
    print("Total taxes raised equals "+str(equilibriumQ*tax))

Source Code