



 
Hi Liz, I don't know how you are to determine the maximum value of these quadratics. For the quadratic y = ax^{2} + bx + c with a negative, the maximum value occurs at x = b/(2a). Maybe you were given this as a formula, maybe you know some calculus and can find this value using a derivative or you can use the symmetry of a parabola and notice that the maximum value occurs half way between the roots. In any case you can use this fact to solve parts A and B of your problem. For each of the expressions find y when x is 8% and 18% and use these values along with the values you found in parts A and B to sketch the graphs requires for part C. I hope this helps,  


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