Question 17, 18, 20, 21. Please help me out with these questions

17. Find all functions whose derivative is equal to Va. 18. Find the function whose instantaneous rate of change at each t is co.2 and whose value at t = 0 is 8. 19. Find the function whose slope at each x is 8x3 - and whose graph passes through (1, 4). 20. The marginal profit function of a company producing and selling r pairs of wool socks per week is MP(x) = -0.1x + 150. If the profit from selling 1000 pairs of socks is $61,000, what is the profit function? What is the profit from selling 1500 pairs of socks? Ans: P(x) = -0.05x2 + 150x -39,000; P(1500) =73,500 21. The rate of production of a certain item, in millions of units per month, is given by P'(t) = Ste- . Find the production function P(t) if P(0) = 5. Ans: P(t) = -4e-12+ 9