Instructor: Dennis DeTurck
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ANNOUNCEMENTS:
Gus, Cole, Jack and I have really enjoyed teaching you this semester. We wish you safe travels, fun holidays and a terrific winter break. See you next year!
I will have "regular" office hours on Tuesdays from 6-7:30 pm, at my place in the Quad, since that's a pretty central location. "Regular" means that during those times, I'm there for my Math 104 students, and I'm not allowed to tell you I'm busy (unless it's with another student). There will be other times that I will announce either in class or by email (and they'll always be posted on this website). You are welcome to stop by at other times (during the day usually in Cohen Hall or in the evening or on weekends in Riepe), but at those times I reserve the right to ask you to come back later if I'm involved with other stuff.
Homework will be assigned before each Thursday, and will be due at Thursday's lecture the following week. You will sometimes need to use a computer to do some of your homework. The course will also have a MyMathLab site that you will need to use to turn in some of your homework (after the first one. To get started using MyMathLab with the licence you got with your textbook, download this link to get started.
Homework will contain instructions for reading. Make sure you do the reading before the class for which it is assigned. I will assume you have done so.
Grading notes: At the end of the semester, everyone who has not withdrawn from the class will get a grade. Incompletes will not be given to avoid F's.
LATE WORK will NEVER be accepted.
1. A; 2. D;
3. C,F;
4. C; 5. F; 6. E; 7. A; 8. C; 9. E; 10. B; 11. C; 12. 14 (which is not one
of the answers); 13. E; 14. B; 15. B
Ways to get help:
Class notes:
Homework and class notes:
Bonus problems and solutions:
Prove that (explain why) log3(11) is an irrational number.
Suppose log3(11) = r
where r = a/b, and a and b are both
(nonzero) integers (this would define
r as a
rational number.) Then
log3(11) = a/b
b log3(11) = a
log3(11b) = a
3a = 11b
So, for log3(11) to be a rational number, there must exist nonzero integers a and an integer b for which the above statement is true. Because the prime factorization of any number is different from that of any other number, and 3a and 11b are examples of numbers that have been simplified to their prime factors, there cannot be positive integers a and b for which 3a = 11b, and so log3(11) cannot be a rational number.
Therefore, log3(11) is an irrational number.
Find the sum of the series:
1 + 1/2 + 1/3 + 1/4 + 1/6 + 1/8 + 1/9 + 1/12 + 1/16 + 1/18 + ...
where the terms are the reciprocals of the positive integers whose only prime factors are 2s and 3s.
Consider the series whose terms are the reciprocals of the positive integers that can be written (in ordinary base 10 notation) without using the digit 0. Show that this seris is convergent and that its sum is less than 90.
and
find its sum.