1 Initial value problems
www.math.pitt.edu › ~sph › 1275Later we will consider initial value problems where there is no way to –nd a formula for the solution. An example was given in the syllabus: y0 = y3 +sint y(0) = 0: It™s not the initial condition that is the problem (it rarely is). The problem is that we can™t do any algebra which puts the equation into the form y0 (t)h(y) = f (t);
1.2 INITIAL-VALUE PROBLEMS
www.personal.psu.edu › bwo1 › coursesthat there exists some interval centered at 2 on which the initial-value problem dy 1/2dx xy, y(2) 1 has a unique solution. In Example 1, Theorem 1.2.1 guarantees that there are no other solutions of the initial-value problems y y, y(0) x3 and y y, y(1) 2 other than y 3e and y 2ex 1, respectively. This follows from the fact that f(x, y) y and
1.2 INITIAL-VALUE PROBLEMS
www.personal.psu.edu/bwo1/courses/Dennis/section1-2.pdfinitial-value problem of the form given in (2). We shall wait until Chapter 4 to address the question of existence and uniqueness of a second-order initial-value problem. THEOREM 1.2.1 Existence of a Unique Solution Let R be a rectangular region in the xy-plane defined by a x b, c y d that contains the point (x 0, y 0) in its interior.