A bookstore is deciding what price it should charge for a certain book. After research, the store finds that if the book's price is dollars (where ), then the number of books sold per month is . What price should the store charge to maximize its revenue?
If s is a real number, then what is the smallest possible value of 2s^2-8s+19?
If t is a real number, what is the maximum possible value of the expression -t^2+8t-4?
Thanks so much
Your first Q is missing some vital info.
2. This is a bowl shaped parabola .....the minimum value for s is - b / 2a = - (-8)/(2(1)) = 4
then subbing s = 4 into the eq yields 2(4)^2-8(4)+19 = 19 4,19
3. This is a dome shaped parabola max is -b/2a = - (8)/(2(-1)) = 4
then subbing t=4 into the eq yields -(4)^2 + 8t -4 = 12 4,12