M251ex1(sp09) - MATH 251 Name: Examination I Student...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
MATH 251 Examination I February 26, 2009 Name: Student Number: Section: This exam has 15 questions for a total of 100 points. In order to obtain full credit for partial credit problems, all work must be shown. Credit will not be given for an answer not supported by work. The point value for each question is in parentheses to the right of the question number. You may not use a calculator on this exam. Please turn off and put away your cell phone. 1 : 2 thru 11: 12: 13: 14: 15: Total: Do not write in this box.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MATH 251 EXAMINATION I February 26, 2009 1. (9 points) Consider the list of diFerential equations below. A. y = y 3 - y 2 B. y ′′′ - y 2 = sin 3 t C. y ′′ + e t y = 1 D. t 2 + y + ( t + y 2 ) y = 0 E. y ′′ - t 3 y + e 2 t y = 0 ±. y ′′ - 2 y + 5 y = 9 - e y G. y + 2 y = π H. y - t 2 y = t ln t ±or each part, write down the letter corresponding to the equation on the list with the speci²ed properties. There is only one correct answer to each part. (a) (3 points) ±irst order linear equation that is not separable. (b) (3 points) Exact equation that is not separable. (c) (3 points) Second order homogeneous linear equation. Page 2 of 11
Background image of page 2
MATH 251 EXAMINATION I February 26, 2009 2. (5 points) Consider the initial value problem sin( t ) y ′′ + tan( t ) y + ty = e t , y ( π 4 ) = 4 π 3 , y ( π 4 ) = - π 4 . Without solving the equation, what is the largest interval in which a unique solution is guar-
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/16/2011 for the course MATH 251 taught by Professor Chezhongyuan during the Spring '08 term at Pennsylvania State University, University Park.

Page1 / 11

M251ex1(sp09) - MATH 251 Name: Examination I Student...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online