7) Find the absolute extreme values of f(x] = x4 -|- 12363 104-3452 on the interval [4, 5 ]. 8) A star fruit grower finds that if she plants 21 trees per acre, each tree will yield 90 bushels of star 'uit. She also estimates that for each additional tree that she plants per acre, the yield of each tree will decrease by 2 bushels. How many trees should she plant per acre to maximize her harvest and what is the maximum harvest