for the cost function you posted, the minimum cost will occur when Q = 0 ... which leads me to believe that the cost function has a sign typo.
TC = 2Q^{2 }+ 158Q - 12000
If the total cost (in £s) function is given by
where Q is the quantity produced
(a) What Q would minimise total costs? Give your answer to 2 decimal places. (b) Use your value in (a) to find the minimum value for total costs. Give your answer to the nearest
pound.
If anyone could go through how to get the answer with me I would be extremely grateful.