Question 1039288
A solar panel manufacturer estimates that the profit y (in dollars) generated by producing x solar panels per month is given by the equation
S(x) = 8x + 0.8x^2 − 0.002x^3 − 4000.
Graph the function in the viewing rectangle [0, 400] by [−10,000, 20,000]. 
For what range of values of x is the company's profit greater than $15,000? (Round your values to the nearest integer. Enter your answer using interval notation.) 
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{{{graph(400,400,0,400,-10000,20000,-0.002x^3+0.8x^2+8x-4000,15000)}}}
Ans:: [217,319]
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Cheers,
Stan H.