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4) Consider the equation f(x) = cosx - 2x = 0. Show that f(x) has a root in the interval [0, 1] and use Newton's method to approximate the 3" root. [Hint: assume the first root x. = 0 and find 3" root x2] [5 marks] 5) An item that is to be sold at a small specialty store in Vancouver has $150 in fixed costs and $2 per item in variable costs. The owners assume they can sell 14 items if they charge $38 each, and 7 items at a price of $73 each. (You may and should assume that demand is a linear function for this problem.) For how many units sold/produced is the marginal profit 36 dollars per item? [5 marks]