Sales tax and cost

Consider the following program:

    def totalCost(a, b):
        cost = 1.08 * (a + b)
    totalCost(38, 14)
    print("The cost will be", cost)

The function totalCost adds two prices and then calculates the sales tax (by multiplying by 1.08). The main program prints out the total cost. Does this program accomplish that successfully? Why or why not? If not, how should it be changed?

I've found that the code doesn't work because the cost is not defined but I'm having an issue trying to correct it.