Math3B Exam #02 Solution Fall 2017

Similar documents
MATH MIDTERM 4 - SOME REVIEW PROBLEMS WITH SOLUTIONS Calculus, Fall 2017 Professor: Jared Speck. Problem 1. Approximate the integral

Math 1B Final Exam, Solution. Prof. Mina Aganagic Lecture 2, Spring (6 points) Use substitution and integration by parts to find:

EXAM. Practice for Second Exam. Math , Fall Nov 4, 2003 ANSWERS

Math 181, Exam 2, Fall 2014 Problem 1 Solution. sin 3 (x) cos(x) dx.

Math 102 Spring 2008: Solutions: HW #3 Instructor: Fei Xu

Prelim 2 Math Please show your reasoning and all your work. This is a 90 minute exam. Calculators are not needed or permitted. Good luck!

2016 FAMAT Convention Mu Integration 1 = 80 0 = 80. dx 1 + x 2 = arctan x] k2

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Math Calculus II Homework # Due Date Solutions

Math 2300 Calculus II University of Colorado

Techniques of Integration

1 Exponential Functions Limit Derivative Integral... 5

D sin x. (By Product Rule of Diff n.) ( ) D 2x ( ) 2. 10x4, or 24x 2 4x 7 ( ) ln x. ln x. , or. ( by Gen.

APPM 1360 Final Exam Spring 2016

Math 2260 Exam #2 Solutions. Answer: The plan is to use integration by parts with u = 2x and dv = cos(3x) dx: dv = cos(3x) dx

1. Evaluate the integrals. a. (9 pts) x e x/2 dx. Solution: Using integration by parts, let u = x du = dx and dv = e x/2 dx v = 2e x/2.

Section: I. u 4 du. (9x + 1) + C, 3

Midterm Exam #1. (y 2, y) (y + 2, y) (1, 1)

AP Calculus BC Chapter 8: Integration Techniques, L Hopital s Rule and Improper Integrals

HAND IN PART. Prof. Girardi Math 142 Spring Exam 1. NAME: key

Math 21B - Homework Set 8

MA 242 Review Exponential and Log Functions Notes for today s class can be found at

Department of Mathematical Sciences. Math 226 Calculus Spring 2016 Exam 2V2 DO NOT TURN OVER THIS PAGE UNTIL INSTRUCTED TO DO SO

FINAL - PART 1 MATH 150 SPRING 2017 KUNIYUKI PART 1: 135 POINTS, PART 2: 115 POINTS, TOTAL: 250 POINTS No notes, books, or calculators allowed.

Integration Techniques for the BC exam

Calculus 2 - Examination

REVIEW: MORE FUNCTIONS AP CALCULUS :: MR. VELAZQUEZ

MATH 101 Midterm Examination Spring 2009

Spring 2011 solutions. We solve this via integration by parts with u = x 2 du = 2xdx. This is another integration by parts with u = x du = dx and

The answers below are not comprehensive and are meant to indicate the correct way to solve the problem. sin

Integration Techniques for the AB exam

Fundamental Trigonometric Identities

Calculus 1: Sample Questions, Final Exam

Trigonometric Identities Exam Questions

MA 114 Worksheet #01: Integration by parts

Integration Techniques for the BC exam

CHAIN RULE: DAY 2 WITH TRIG FUNCTIONS. Section 2.4A Calculus AP/Dual, Revised /30/2018 1:44 AM 2.4A: Chain Rule Day 2 1

MATH 31B: MIDTERM 2 REVIEW. sin 2 x = 1 cos(2x) dx = x 2 sin(2x) 4. + C = x 2. dx = x sin(2x) + C = x sin x cos x

1969 AP Calculus BC: Section I

PRELIM 2 REVIEW QUESTIONS Math 1910 Section 205/209

SOLUTIONS TO THE FINAL - PART 1 MATH 150 FALL 2016 KUNIYUKI PART 1: 135 POINTS, PART 2: 115 POINTS, TOTAL: 250 POINTS

VANDERBILT UNIVERSITY MAT 155B, FALL 12 SOLUTIONS TO THE PRACTICE FINAL.

CALCULUS II MATH Dr. Hyunju Ban

HOMEWORK SOLUTIONS MATH 1910 Sections 8.2, 8.3, 8.5 Fall 2016

Honors PreCalculus Final Exam Review Mr. Serianni

DRAFT - Math 102 Lecture Note - Dr. Said Algarni

University of Waterloo Final Examination MATH 116 Calculus 1 for Engineering

Calculus II Practice Test Problems for Chapter 7 Page 1 of 6

Solutions to Exam 1, Math Solution. Because f(x) is one-to-one, we know the inverse function exists. Recall that (f 1 ) (a) =

MATH section 3.1 Maximum and Minimum Values Page 1 of 7

Integration Techniques for the AB exam

cosh 2 x sinh 2 x = 1 sin 2 x = 1 2 cos 2 x = 1 2 dx = dt r 2 = x 2 + y 2 L =

Transition to College Math

Math 122 Fall Unit Test 1 Review Problems Set A

Handout 1. Research shows that students learn when they MAKE MISTAKES and not when they get it right. SO MAKE MISTAKES, because MISTAKES ARE GOOD!

Mathematics 104 Fall Term 2006 Solutions to Final Exam. sin(ln t) dt = e x sin(x) dx.

Math 180, Exam 2, Spring 2013 Problem 1 Solution

TOTAL NAME DATE PERIOD AP CALCULUS AB UNIT 4 ADVANCED DIFFERENTIATION TECHNIQUES DATE TOPIC ASSIGNMENT /6 10/8 10/9 10/10 X X X X 10/11 10/12

6.1 Reciprocal, Quotient, and Pythagorean Identities.notebook. Chapter 6: Trigonometric Identities

Formulas From Calculus

( ) + ( ) ( ) ( ) Exercise Set 6.1: Sum and Difference Formulas. β =, π π. π π. β =, evaluate tan β. Simplify each of the following expressions.

A MATH 1225 Practice Test 4 NAME: SOLUTIONS CRN:

Preface. Computing Definite Integrals. 3 cos( x) dx. x 3

Math Section 4.3 Unit Circle Trigonometry

Chapter 7: Techniques of Integration

Part I: Multiple Choice Mark the correct answer on the bubble sheet provided. n=1. a) None b) 1 c) 2 d) 3 e) 1, 2 f) 1, 3 g) 2, 3 h) 1, 2, 3

du u C sec( u) tan u du secu C e du e C a u a a Trigonometric Functions: Basic Integration du ln u u Helpful to Know:

(ii) y = ln 1 ] t 3 t x x2 9

90 Chapter 5 Logarithmic, Exponential, and Other Transcendental Functions. Name Class. (a) (b) ln x (c) (a) (b) (c) 1 x. y e (a) 0 (b) y.

McKinney High School AP Calculus Summer Packet

Math 141: Trigonometry Practice Final Exam: Fall 2012

Calculus 152 Take Home Test 2 (50 points)

171, Calculus 1. Summer 1, CRN 50248, Section 001. Time: MTWR, 6:30 p.m. 8:30 p.m. Room: BR-43. CRN 50248, Section 002

Math Section 4.3 Unit Circle Trigonometry

MATH 104 FINAL EXAM SOLUTIONS. x dy dx + y = 2, x > 1, y(e) = 3. Answer: First, re-write in standard form: dy dx + 1

1993 AP Calculus AB: Section I

du u C sec( u) tan u du secu C e du e C a u a a Basic Integration Trigonometric Functions: du ln u u Helpful to Know: Inverse Trigonometric

sin cos 1 1 tan sec 1 cot csc Pre-Calculus Mathematics Trigonometric Identities and Equations

12) y = -2 sin 1 2 x - 2

Instructions: No books. No notes. Non-graphing calculators only. You are encouraged, although not required, to show your work.

Chapter 2 Overview: Anti-Derivatives. As noted in the introduction, Calculus is essentially comprised of four operations.

2 nd ORDER O.D.E.s SUBSTITUTIONS

Inverse Trig Functions

= π + sin π = π + 0 = π, so the object is moving at a speed of π feet per second after π seconds. (c) How far does it go in π seconds?

Trigonometry LESSON SIX - Trigonometric Identities I Lesson Notes

Mathematics 132 Calculus for Physical and Life Sciences 2 Exam 3 Review Sheet April 15, 2008

Math 113/113H Winter 2006 Departmental Final Exam

Using the Definitions of the Trigonometric Functions

Lesson 5.3. Solving Trigonometric Equations

Chapter 2 Section 3. Partial Derivatives

Math 162: Calculus IIA

Math 132 Exam 3 Fall 2016

Math 222 Spring 2013 Exam 3 Review Problem Answers

Math RE - Calculus I Trigonometry Limits & Derivatives Page 1 of 8. x = 1 cos x. cos x 1 = lim

(a) Show that there is a root α of f (x) = 0 in the interval [1.2, 1.3]. (2)

Exam 2 Solutions, Math March 17, ) = 1 2

MAC 2311 Final Exam Review Fall Private-Appointment, one-on-one tutoring at Broward Hall

Math 2250 Final Exam Practice Problem Solutions. f(x) = ln x x. 1 x. lim. lim. x x = lim. = lim 2

1. The following problems are not related: (a) (15 pts, 5 pts ea.) Find the following limits or show that they do not exist: arcsin(x)

Transcription:

. Integrate. a) 8 MathB Eam # Solution Fall 7 e d b) ln e e d

. Integrate. 6 d

. Integrate. sin cos d

4. Use Simpsons Rule with n 6 to approimate sin d. Then use integration to get the eact value. 6 6

5. Integrate a) cos 5 sin d b) tan 5 sec d

6. Integrate using trigonometric substitution. a) 4 4 d b) 5 d

7. Solve the initial value problem using the integrating factor method. dy sec y sec tan y 4 d

8. Integrate. ln a) d b)

MathB Practice Eam #. Integrate. a) e d b) tan d

. Integrate. a) d (Hint: Let u ) b) 4sin cos d

. Use Simpsons Rule with n 6 to approimate get the eact value. cos d. Then use integration to

4. Integrate. a) 4 6 tan d b) sin cos d

5. Integrate using trigonometric substitution. a) 4 9 d b) 4 7 d (First complete the square.)

6. Show that the solution to the initial value problem is a hyperbolic function. Use the integrating factor method. dy d y e y

7. Integrate. ln a) d b) e d

MathB Eam # Review Problems Solutions provided by Romeo Mercado and Matthew Staley of the Learning Assistance Program at Saddleback College. March 9,. Integrate. sin a) d b) π 7 sin e e 4 ( e ) d + C c) 4 + ln ( ) ln tan d + C d) e) + 4 d e d f) tan d ln + 4 + + C e e + C π π ln + 6. Integrate. π e π cos ln d e b) a) ( ). Integrate. e d e + ln a) π 4 tan d b) 5 6 tan tan tan d + tan + C 5 c) + 6 d + 4 ln + 6 + C e d) ln d e 9 + 4. Integrate. a) cos(ln ) d cos(ln ) + sin(ln ) + C b) π 4 tan d ln 5 c) e d (Let u ) d) 4 e e + e + C 4 e ln d e) e π 4 6 tan d π 5 4

5. Integrate. 6 4 4 4 4 a) tan sec d b) sin cos d c) cot csc d 9 7 tan tan + + C 9 7 7 5 cos cos + C 7 5 7 5 cot cot + C 7 5 d) + 4 d e) 9 d f) ( + ) 4 9 / d + 4 + C 4 9 sin + C + 4 g) d + 4 ln + ln ( + 4) tan + C 6. Integrate. (Let u tan ) a) d + sin + C tan + h) + ( )( ) d b) d sin 4cos + i) d 9 6 4 ln + ln + + + C 5 5 5 ( + ) ln 5 tan tan + ln + ln + C + C 7. Use Simpsons Rule with n 6, to approimate π sin d. Then use integration to get the eact value. Compare the two results. π 8. Integrate. a) d + 9. Solve the initial value problem. dy b) e d c) ln d π π y+ cos y y y a) y e e ; y ( ) b) y ; y ( ) d c) y ; y ( ) y ln + y 4e y + sin y + π

Math B Eam # Review Problem Solutions Mr. Perez, Spring Solutions by Romeo Mercado and Matthew Staley, LAP, Saddleback College March 9,

I highly recommend that the student first attempt these problems on their own before looking at the solutions.. (a) / sin () π/6 d u du u π/6 ( (π ) ) ( ) π π 6 6 7 u sin () u π 6 du d u. (b) e d e 4 u du sin (u) + C sin (e ) + C u e du e d du e d. (c) [ 4 + (ln ) ] d u ln u ln Note: match constant with u-sub u du d 4 + (u) du 4 + 4u du 4( + u ) du + u du tan (u) + C tan ( ) ln + C

. (d) + 4 d sec θ dθ 4 tan θ + 4 4 tan θ tan θ d sec θ dθ + 4 θ sec θ dθ 4(tan θ + ) }{{} 4 sec θ sec θ dθ sec θ sec θ dθ sec θ (sec θ + tan θ) (sec θ + tan θ) dθ sec θ + sec θ tan θ sec θ + tan θ dθ u sec θ + tan θ, du sec θ tan θ + sec θ dθ u du ln u + C ln sec θ + tan θ + C ln + 4 + + 4 + + C ln + C

. (e) e d Let w dw d dw d w dw d we w dw u w dv e w dw du dw v e w [ we w ] e w dw [we w e w ] + C [ e e ] + C e [ ] + C. (f) tan d Let w, w, dw d dw d w dw d w(tan w)w dw w tan w dw Integration by parts u tan w dv w dw du v + w w

w tan w w + w dw Let z + w w, z, 4 z w dz w dw dz w dw Note that w w w in the integral above so that the z-substitution gives: w tan w w tan w 4 z z 4 z dz ( ( ) ) tan tan () ( z ln z dz ) 4 ( π π ) ( ) 4 ln(4) [ ln()] 4 π π 6 + ln(4) ln() (Note that ln(4) ln( ) ln()) π π 6 + ln() ln() π π 6 + ln() π π 6 + ln() 4

. (a) e π/ cos(ln ) d Let w ln, w, π dw d dw d e w dw d (w ln e w ) π/ e w cos w dw ( ) u cos w du sin w dw dv e w dw v e w e w cos w e w cos w π/ π/ + π/ π/ e w ( sin w) dw e w sin w dw u sin w du cos w dw dv e w dw v e w e w cos w π/ + e w sin w π/ π/ e w cos w dw }{{} Same as ( ) above, add to both sides π/ e w cos w dw e w cos w π/ + e w sin w π/ [ e π/ cos π ] [ e cos + e π/ sin π ] e sin [ ] + [e π/ ] e π/ π/ e cos w dw ( e π/ ) 5

. (b) e d e u dv e d du ln d v e e d + (ln ) e d e e (ln ) d e (ln ) e d } {{ } Add to both sides [ ] ( + ln ) e d e e e e e d e + ln. (a) tan d u tan dv d du + d v tan + d + + + + + + tan + d tan ( tan ) [ tan tan ] ([ tan ] [ tan ]) [ π ] ( π ) 4 4 + π 8 + π 8 π 8 π 4 6

. (b) tan 6 d ( Idea is to break off tan as sec ) tan 4 tan d tan 4 (sec ) d tan 4 sec d tan 4 d tan 4 sec d tan tan d tan 4 sec d tan (sec ) d tan 4 sec d (tan sec tan ) d tan 4 sec d tan sec d + tan d tan 4 sec d tan sec d + (sec ) d }{{} utan dusec d u 4 du u du + sec d d u5 5 u + tan + C tan5 5 tan + tan + C 7

. (c) + 6 d ( + + ) d Complete the square for + ( + + ) d ( + ) 6 d Now for a Trig Sub: I want ( + ) 6 sec θ ( + ) 6 sec θ ( + ) 4 + 4 sec θ sec θ d 4 sec θ tan θ dθ ( + ) θ 4 ( + ) 6 + 6 4 4 sec θ tan θ dθ 6 sec θ 6 sec θ tan θ dθ 6(sec θ ) 4 sec θ tan θ dθ 6 tan θ 4 6 sec θ tan θ dθ 8

4 cos θ cos θ sin θ dθ sin θ dθ csc θ dθ ln csc θ cot θ + C Use the triangle found above ln ( + ) + 6 4 + 6 + C ln + 4 + 6 + C 9

. (d) e ln d u ln dv d du d v / / ln e e e / ln e / ln / d e / d ( ) / e ([ ] [ ]) e/ ln e ()/ ln 4 ( e / /) 9 ( ) e/ 4 9 e/ + 4 9 6 9 e/ 4 9 e/ + 4 9 9 e/ + 4 9 9 [ e / + ]

4. (a) cos(ln ) d Let w ln ( Similar to a above) dw d dw d e w dw d (w ln e w ) e w cos w dw ( ) u cos w du sin w dw dv e w dw v e w e w cos w e w cos w + e w ( sin w) dw e w sin w dw u sin w du cos w dw dv e w dw v e w e w cos w + e w sin w e w cos w dw }{{} Same as ( ) above, add to both sides e w cos w dw e w cos w + e w sin w + C e ln cos(ln ) + e ln sin(ln ) + C cos(ln ) + sin(ln ) + C cos(ln ) d cos(ln ) + sin(ln ) + C

4. (b) tan d u tan dv d du + d v tan tan tan + d u +, u, du du d u d ln u ( tan tan ) (ln ln ) π 4 ln π 4 ln / π 4 ln

4. (c) 5 e d 4 e d u u 4 du d du d u e u du ( u e u e u + e u) + C ( 4 e e + e ) + C Derivative Integral u u + + e u e u e u e u 4. (d) e 4 e ln d e 4 e ln d u ln d e, e 4 u, 4 du d 4 u du ( u ) 4 4 ( 4 ) (6 4) 4 4

4. (e) π/4 tan 6 d (See b Above) ( tan 5 5 tan ) π/4 + tan [ tan 5 π 4 5 tan π 4 + tan π 4 π ] [ tan 5 4 5 tan ] + tan [ 5 ] + π [ + ] 4 5 5 5 + 5 5 π 4 5 π 4 5. (a) tan 6 sec 4 d tan 6 (sec )(sec ) d tan 6 ( + tan )(sec ) d (tan 6 + tan 8 ) sec d u tan, du sec d u 6 + u 8 du u7 7 + u9 9 + C tan7 + tan9 + C 7 9 4

5. (b) sin cos 4 d sin (sin ) cos 4 d sin ( cos )(cos 4 ) d sin (cos 4 cos 6 ) d u cos, du sin d u 4 u 6 du u 6 u 4 du u7 7 u5 5 + C cos7 cos5 + C 7 5 5. (c) cot 4 csc 4 d cot 4 (csc )(csc ) d cot 4 ( + cot )(csc ) d (cot 4 + cot 6 ) csc d u cot, du csc d ( ) u u 4 + u 6 5 du 5 + u7 + C cot5 cot7 + C 7 5 7 5

5. (d) + 4 d 4 tan θ tan θ d sec θ dθ tan θ + 4 θ sec θ dθ 4 tan θ 4 tan θ + 4 sec θ dθ 4 tan θ 4(tan θ + ) sec θ dθ 4 tan θ( sec θ) sec θ dθ 4 tan θ 4 cos θ cos θ sin θ dθ cos θ 4 sin θ dθ u sin θ, du cos θ dθ 4 u du ( ) + C ( ) + C 4 u 4 sin θ ( ) 4 csc θ + C + 4 + 4 + C + C 4 4 6

5. (e) 9 d 9 sin θ sin θ d cos θ dθ sin θ θ 9 9 9 sin θ 9 sin θ ( cos θ) dθ 9( sin θ) 9 sin θ (cos θ) dθ 9 cos θ sin θ (cosθ) dθ cos θ sin θ (cos θ) dθ cos θ sin θ dθ sin θ sin θ dθ sin θ sin θ sin θ dθ csc θ dθ cot θ θ + C 9 sin + C 7

5. (f) Z / d (4 + 9)/ / Z u 4 + 9 d (4 + 9)/ (u 9) 4 du 8 d du d 8, 8 Z 6 (u 4 9) u/ 9 Z Z 6 9 u 9, 6 du u 9 du u/ u/ 6 u / 9u / du 9 u/ 9u / / / 8 u+ u 6 6! 9! 9 8 8 6 + 9+ 6 9 8 6+ (6 + 6) [ + ] 6 8

5. (g) + 4 + 4 d + 4 ( + 4) d A + B + C + 4 d Partial Fraction Decomposition: Find A, B, C : + 4 ( + 4) A + B + C + 4 + 4 A( + 4) + (B + C) (A + B) + (C) + 4A [Association] A + B C 4 4A + B A B + + 4 + + 4 + 4 d d + Will do each integral separately: + 4 d + 4 d d ln + 4 d u du ln u ln + 4 ln( + 4) u + 4 du d du d 9

+ 4 d want 4 tan θ tan θ tan θ tan θ d sec θ dθ sec θ dθ 4 tan θ + 4 sec θ dθ 4(tan θ + ) sec θ sec θ dθ dθ θ tan Putting it all back together gives: d + + 4 d + 4 d ln + ln( + 4) tan + C

5. (h) ( )( + ) d A + B + + C ( + ) d ( )( + ) A + B + + C ( + ) A( + ) + B( )( + ) + C( ) A( + 4 + 4) + B( 6) + C( ) (A + B) + (4A B + C) + (4A 6B + C) Association gives us the following system of equations: A + B () 4A B + C () 4A 6B C () Eliminate C by () + (): A B + C 4A 6B C 6A 9B + C (4) Add 9 () + (4): 9A + 9B 9 6A 9B 5A 9 A 9 5 B 6 5

To find C, use equation (): 4A B + C ( ) 9 4 6 5 5 + C 6 5 6 5 + C 5 + C C 4 5 A + B + + C ( + ) d 9 5( ) + 6 5( + ) 4 5( + ) d 9 5 6 d + 5 + d 4 5 ( + ) d }{{ } u+, dud 9 5 9 5 6 ln + 5 ln + 4 5 u du 6 ln + 5 ln + 4 ( ) + C 5 u 9 5 ln + 6 5 ln + + 4 5( + ) + C

5. (i) + d Use Long Division + + d + d + d }{{} Partial Fraction Decomposition + ( ) A + B + A( ) + B + (A + B) A A + B + B B A d + + d ln + ln + C

6. (a) + sin d Let u tan tan u tan u du d + u Note : sin() sin cos + u u sin sin cos + sin cos d ( ) +u du ( ) ( u + +u +u ) ( ) + u + u du +u ( ) + u +u +u +u du ( ) ( + u ) + u + u + u du u + u + du du w u + dw du (u + ) ( w dw ) + C w u + + C tan + + C 4

6. (b) sin 4 cos d Let u tan tan u tan u du d + u + u u Note : sin() sin cos sin sin cos ( ) ( ) u + u + u u + u cos() cos sin cos() cos ( ) sin + u ( ) u u u + u ( ) ( ) ( u +u 4 u ) + u +u 6u 4+4u +u ( ) + u du ( ) + u 6u 4 + 4u + u (u u ) du du du (u )(u + ) du }{{} Partial Fraction Decomposition A u + B u + du 5

A(u + ) + B(u ) u(a + B) + (A B) A + B A B A B ( B) B 4B B 5B 5 B A 5 A u + B u + du 5 u du 5 }{{} wu+, dwdu u + du } {{ } zu+, dzdu 5 w dw 5 z dz 5 ln w 5 z + C 5 ln w z 5 ln u u + + C w u, z u + 5 ln tan tan + + C u tan + C 6

Z π sin d 7. (a) a bπ b a π π 4 n 6 6 y sin sin π 6 π 6 π 6 π π 6 π 4π 6 π π sin π π π 5π 6 6π 6 sin π6 π sin 5π 6 π 5π 6 π 6 π sin π sin π 5π 6 π 6 π 6 π π 5π π sin π π π Simpon s Rule: Z π b a [y + 4y + y + 4y + y4 + 4y5 + y6 ] n " # π π π π π 5π +4 + +4 + +4 + 6 6 " # " # π 5 π π π π π 5π 4π +.495.98467 + + π + + 8 6 8 6 sin d 7

7. (b) π sin d u du d dv sin d v cos d cos π π ( cos ) d cos π + sin π [π cos π ( cos )] + [sin π sin ] π( ) + π Comparing the two results we see that : π.98467.569. 8

8. (a) + + d + + d + + d lim a a b d + lim + b + d lim a tan a + lim b tan b lim a (tan tan a) + lim b (tan b tan ) lim a ( tan a) + lim b (tan b ) ( π ) ( π ) + π + π π 8. (b) e d lim a a e d u du d dv e d v e ( lim e a a ( ) lim e e a a a ) e d lim a ((e e ) (ae a e a )) lim ( a aea + e a ) lim a aea } {{ } + lim a ea }{{} 9

8. (c) ln d lim a + a ln d u ln dv dv du d v ( lim ln a + ( lim ln a + ) a a d a a ) d ( lim ln a + a ) a lim (( ln a ln a) ( a)) a + lim a ln a + lim a a } + a {{}}{{ + } ln a lim a + a }{{}, LH lim a + a a lim a +( a) +

9. (a) y e y e y ; y() Use Separation of variables y e y + e y dy d ey ( + ) dy ( + ) d ey e y dy ( + ) d e y + + C e y + C Plug in the initial value to find the constant C: e () + C + + C C Now solve for y: e y + ) ln e y ln ( + ) y ln e ln ( + ) y ln ( + ) y ln ( +

9. (b) dy y ; y() Use Separation of variables d + y dy d + y ( + y) dy d + y dy d ln + y + C + + C Plug in the initial value to find the constant C: ln + () + C Solve for y: ln 4 C ln + y + ln 4 e ln +y e +ln 4 + y e e ln 4 y 4e

9. (c) y y + cos y ; y() π Use Separation of variables dy d y + cos y (y + cos y) dy d (y + cos y) dy d y + sin y + C y + sin y + C Plug in the initial value to find the constant C: (π) + sin π + C π + C π C y + sin y + π We cannot solve eplicitly for y here so we are done.