Fall 2009 Math 151 2 Week in Review X 1. Setion 4.6 Find the exat values of eah of the following: ourtesy: David J. Manuel (a) (overing 4.5, 4.6, 4.8) cos−1 √ ! 3 − 2 arcsin(−1) 4 −1 () cot sin 5 3 (d) sin 2 arcsin 5 1−x −1 Compute lim tan x→0 2x2 (b) 1 1. 2. 3. 4. Setion 4.5 Strontium-90 is a radioative isotope with a half-life of 25 years. If there are 20 mg of Strontium present, how muh remains after 15 years? When will there be only 5 mg left? 2. 3. Aording to UN data, the world population at the beginning of 2000 was 6 billion and growing at a rate of 1.6%. Assuming an exponential growth model, estimate the world population at the beginning of 2010. 4. Use (b) 3 1. () (d) 1 f (x) = arcsin x 1 y = x tan−1 (2x) − ln(1 + 4x2 ) 4 t3 − t2 − t + 10 t→−2 t2 + 3t + 2 1 − cos x lim x→0 2x2 lim+ x ln x lim x→0 lim (1 + e2x )1/x x→∞ The 4.3 WIR used the inter ompound r mt est formula A = P 1 + . Find lim A m→∞ 1 prove Compute the following limits: (b) 2. to Setion 4.8 (a) A tank initially ontains 100kg of salt dissolved in 2000 liters of water. Pure water enters the tank at a rate of 50 L/min and the mixed solution is drained from the tank at the same rate. Find the amount of salt in the tank after t minutes. funtions Dierentiate and simplify the following: (a) Newton's Law of Cooling states that the rate of hange in the temperature of an objet is proportional to the differene in temperature between the objet and its surroundings. A up of oee with an initial temperature of 90◦ C is in a room that is held at a onstant temperature of 20◦ C . If the liquid ools to 75◦ C after 5 minutes, what will its temperature be after 15 minutes? inverse d 1 (tan−1 x) = dx 1 + x2 m