############################################################## ############################################################## ############################################################## ############################################################## ############################################################## ### ### ### ### ### NO CLASS WEDNESDAY, December 9, 2009 ### ### ### ### ### ### Test four will still be on the last day ### ### ### ### ### ### ### ### ### ### of class which will be Friday, December 11, 2009. ### ### ### ### ### ### ### ### ### ### The practice test and answers is available on the web. ### ### ### ### ### ### ### ### ### ############################################################## ############################################################## ############################################################## ############################################################## ############################################################## Instructor Hentzel Office Phone: 515-294-8141 E-mail: hentzel@iastate.edu Math Department Fax: 515-294-5454 http://www.math.iastate.edu/hentzel/class.165.09 Textbook: Calculus by Varberg, Purcell, Rigdon, ninth edition. Wednesday, December 9 REVIEW Practice TEST 4 The actual TEST 4 is Friday, December 11, 2009 During Class 7:30 to 9:00 AM 1. (a) Give the definition of y = ln(x). x (b) Give the definition of y = e x (c) If (a,b) is on the curve, y = e , what is the derivative of y = ln(x) when x = b. 2. Express the following as rational numbers. 2 ln(3/4) (a) e 3 (b) ln( Sqrt[ e ] ) (c) Log (27/8) 3/2 3 (d) Log Sqrt[a ] 2 a 3. Find the following derivatives. (a) y = ln(x) x (b) y = e (c) y = Sinh[x] (d) y = Cosh[x] (e) y = Tanh[x] (f) y = ArcSin[x] (g) y = ArcCos[x] (h) y = ArcTan[x] (g) y = ArcSec[x] / 4. Derive the solution of y = -a y + b (a >= 0) 5. A population started with 64 individuals and every 13 years the population doubles. (a) Write the equation 6. Room temperature is 20 degrees centigrade. A hot brick starts at 200 degrees centigrade and cools to 160 degrees centigrade in 5 minutes. (a) How hot will it be after a total of 30 minutes? (b) When will it be 25 degrees centigrade? 7. A brick starts at 300 degrees at t = 0. At t = 1 it is 210 degrees. At t = 2 it is 192 degrees. What is the ambient temperature? 8. Find the derivative of 13 15 2 (x+3) (x-5) (x ) y = --------------- e 4 (x+29) 9. Find the derivative. Do not simplify. 2 (x + 6 x + 2 ) (a) e 2 (b) ln( 14 x + 3 x ) (c) ArcTan[ 3/x ] (d Sinh[ Sqrt[x] ] 10. Evaluate these integrals. x/2 e (a) INT -------- dx x 1 + e Sinh[x] (b) INT ----------- dx Cosh[x] 1 (c) INT --------------- dx _ _ | x 2 | Sqrt| 1-(---) | |_ 3 _| Sqrt[x] e (d) INT -------------- dx Sqrt[x] 11. Give the formula for interest at r% for n years for these compounding frequencies. (a) Yearly (b) Monthly (c) Daily (d) Instantaneously x -x e - e 12. (a) Find the inverse function for y = -------- 2 x -x e - e (b) Find the derivative of the inverse function of y = -------- 2 13. A tank has 100 gallons of water and contains 5 pounds of dissolved salt. Water with 1 pound of salt per gallon flows into the tank at 2 gal per minute and the well mixed solution drains out of the tank at 2 gallons per minute. (a) Write the differential equation for the amount of salt in the tank at time t. (b) How much salt will be in the tank after 30 minutes.