Math 1700 Distance: More Tips for Assignment 2

Published: Wed, 01/30/13


 
Actually, I made a mistake yesterday (sorry, I have the flu right now).  The function in 2(d) is an odd function.  Although there is a typo that does render it impossible. You can just assume there is supposed to be a du on the end of the integral, then everything would be fine.  Unlike what I said yesterday, in fact, cos(-x) = cos(x) meaning that cosine is an even function.  It is sine that is the odd function since sin(-x) = -sin(x).  You can therefore prove that the function given in (d) is odd.
 
Please note that I am now taking registrations for my midterm exam prep seminars.  Please click this link for more info and to register, if you are interested.  Sorry, I don't offer a seminar for Math 1700.
Grant's Exam Prep Seminars 
 
Did you read my tips on how to do well in Math 1700 Distance?  If not, here is a link to those important suggestions:
How to do Well in Math 1700 Distance 
 
Tips for Assignment 1
Even if you are not taking the distance course, I think it is very useful for all Math 1700 students to attempt these hand-in assignments.  In general, the assignments can be quite demanding and really force you to solidify your math skills.  However, the fact is that the distance course covers the topics in a different order from the classroom lecture sections, so I would not advise classroom students to look at this assignment until they have studied the relevant lessons in class.
 
Here is a link where you can download a copy of Assignment 2:
Math 1700 Distance Assignment 2 (Jan 2013) 
 
Note that you need to study Lesson  4(The Method of u Substitution), Lesson 5 (Area between Two Curves) and Lesson 6 (Volumes) from my Calculus 2 book to prepare for this assignment.  I think you should find this assignment fairly straightforward if you do thoroughly study and do all the Practise Problems I give you in these lessons. 
 
Don't have my book? You can download a sample containing two lessons here (unfortunately, the sample contains lessons 1 and 11):
 
Question 1 is integration obviously.  Hint: you will use u substitution for some but not all of these three integrals.  If you do use u sub to solve part (c), make sure you don't actually use u because that variable is already in the problem.  You will have to use a different letter.
 
Question 2 is more of the same, but this time they are definite integrals.  Some people change the endpoints to u values if they are using u substitution to solve a definite integral.  I do not advise this.  I suggest, that you write down the indefinite integral first and solve it.  Then, return to the definite integral and sub the endpoints into your solution. 
 
Some key facts you should know to properly compute the definite integrals in this problem:
 
elna = a will come into play.  Watch out for the chance to use log laws too.
ln ab = b lna
 
Note also that if you are computing the definite integral from -a to a of an odd function, the integral is zero.  Click this link for more info:
Odd functions and integrals 
 
Also note that cosine is an even function since cos(-x) = cos(x).
Although not relevant to this question, sin(-x) = - sin(x), meaning that sine is an odd function.
 
You will need to prove that the function given in question 2(d) is an odd function.
 
Question 3 is  not an integral problem.  You cannot use methods of integration to solve it.  First, separate the problem into two different integrals by splitting the 3 term away from the square root term.  Now draw a graph of each of these two functions for the region between -2 and 2.  (Draw a graph of y = 3 and a separate graph of y = square root of (4 - x2).)  You should now be able to compute the area between the graph and the x-axis from x = -2 to x = 2 in each case using basic geometry (area of a rectangle, area of a circle).
 
Question 4 is like my questions in Lesson 5.  Make sure you do draw the required graph and carefully identify the region to shade and compute. You will need to separate the problem into more than one integral, like I do in my question 2.  Take each pair of the three curves and set them equal to each other to find the points of intersection.  Keep in mind that you are told that x > 0, so do not shade any regions where x is negative.
 
Question 5 is like my questions in Lesson 6.
 
Question 6 is using the average value formula that I mention at the top of page 4 in my book and I think shows up as one of the homework questions in Lesson 2.  Be sure to notice that the formula uses minutes as its unit for time in your problem.