MATH 251 Midterm: MATH 251 PSU C251Exam 1(fa05)
Document Summary
October 12, 2005 answer key to first exam. The point value of each question is indicated either at the beginning of each question or at the beginning of each part where there are multiple part. The use of calculators, books, or notes is not permitted on this exam. Please turn o your cell phone before starting this exam. 1: 2pt consider the following di erential equation y = y + 2t. Without solving it, determine the slope of the tangent line to the solution at the point (1, 2). 2pt for plugging (1, 2) into f (t, y) gives 2 + 2(1) = 4. Give 1pt for 1 + 2(2) = 5: 2pt find the wronskian w (y1, y2) of the functions y1 = sin t and y2 = cos t. 2pt for (2/e)ecos t. 1pt for anything else having the form ?ecos t.
