The most straightforward way to obtain the expression for cos(2x) is by using the "cosine of the sum" formula: cos(x + y) = cosx*cosy - sinx*siny. cos(2x) = cos² (x) - (1 - cos²(x)) = 2cos²(x) - 1. = 2cos²(x) - 1.
<span>the x is supposed to represent the amount of miles driven in that car and the numbers in the paranthesis are supposed to be the price of the car or rental cost</span>
