In a given year, the U.S. federal income tax owed by a married couple filing jointly can be found from the following table (Source: Internal Revenue Service, Form 1040 Instructions).
(a) For incomes up to $151,900, write the piecewise defined function T with input x that models the federal tax dollars due as a function of x, the taxable income dollars earned.
(b) Use the function to find T(70,000).
(c) Find the tax due on a taxable income of $100,000.
(d) A friend tells Jack Waddell not to earn any money over $75,300 because it will raise his tax rate to 25% on all of his taxable income. Test this statement by finding the tax due on $75,300 and $75,300 + $1. What do you conclude?
