MATH 108 GCC Explicit Solution & Separation of Variables Exam Practice

Description

You don’t need to solve every questions. Please solve #1,2,5 first and then after that solve as many as you can from backword for 1 hour. I need asap so once you solve one problem please send me thank you.

1 attachmentsSlide 1 of 1attachment_1attachment_1

Unformatted Attachment Preview

Math 108 – Exam # 1 – Fall 2020
Rules
•
•
•
•
•
•
•
You may use your textbook and your class notes during the exam.
You need to follow the notation used in our textbook and in our class notes.
You may not use the internet, a smart device (cellphone, watch, etc.), any apps or other
resources to find solutions. Using any of those resources will result in a 0 on the exam
and a report of cheating will be filed with the college.
You are not allowed to collaborate with anyone during the exam.
You must show all work, justify your answers, and write legibly to receive full credit.
A correct answer with unsupported work is an automatic zero on the problem.
You may be selected after the exam to have a private Zoom session with your professor
to explain your work on a problem.
1. Find a general explicit solution to the differential equation.
𝑡
𝑑𝜃
= 3𝜃
𝑑𝑡
2. Consider the initial value problem 𝑦 ′ (𝑡) + 𝑡𝑦 = 𝑦, 𝑦(1) = −2.
a) Determine the independent and dependent variables.
b) Solve the initial value problem using the method of separation of variables.
3. Determine the constant k so that the equation is exact. Then solve the resulting
equation.
(2𝑥 − 𝑦𝑠𝑖𝑛 𝑥𝑦 + 𝑘𝑦 4 )𝑑𝑥 − (20𝑥𝑦 3 + 𝑥𝑠𝑖𝑛 𝑥𝑦)𝑑𝑦 = 0
4. Determine whether the Existence and Uniqueness Theorem (Theorem 1 in our
textbook) implies that the given initial value problem has a unique solution.
√𝑦
𝑑𝑦
= √𝑥
𝑑𝑥
, 𝑦(1) = 1
5. Consider the initial value problem 𝑦
𝑑𝑥
𝑑𝑦
2
+ (1 + 𝑦)𝑥 = 𝑒 −𝑦 sin 2𝑦, 𝑥(𝜋) = 𝑒 𝜋
a) Determine the independent and dependent variables, and whether the equation is
linear or nonlinear.
b) Solve the initial value problem.
6. A tank initially contains 100 liters of pure water. A mixture containing a concentration of
8 grams/liter of salt enters the tank at a rate of 3 liters/min. and the well-stirred mixture
leaves the tank at the same rate. Let A(t) be the amount of salt in the tank. Determine the
amount of salt in the tank at any time, t. How much salt is present after 1 hour?

Purchase answer to see full
attachment

Tags:
differential equation

separation of variables

Initial value problem

explicit solution

Uniqueness Theorem

User generated content is uploaded by users for the purposes of learning and should be used following Studypool’s honor code & terms of service.