The function of time A(t) = 0.008t³ - (0.175 + 0.00125*N)t² + 0.96t approximates the concentration of some drug (in tenth of percent) in an average person's bloodstream t hours (0 t 8 h) after taking two pills. Find the time t at which the concentration of the drug is a maximum. Use quadratic formula t_1,2 = [-b (b² - 4ac)^1/2]/(2a)

_______ ________

-b + b² - 4ac -b - b² - 4ac

(2a) t₁ = --------------------- t₂ = --------------------- (2b)

2a 2a

for finding the roots of quadratic equation A'(t) = at² + bt + c = 0 that you obtain. Consider only a solution that fits in the given time interval. Present the time t with six digitsafter the decimal dot.) What is the maximum value of the concentration?