Direction Fields

Given a first-order differential equation of the form \(\dot{y} = f(t,y),\) sketch the direction field for that differential equation, and use the direction field to sketch the curve of an approximate particular solution given an initial condition.
  1. Consider the differential equation \(\dot y = t-\frac{1}{2}y\).
    1. Sketch a direction field for this differential equation for \({-6 \lt y \lt 6}\) and \({-6 \lt t \lt 6\,.}\)
    2. Using your direction field, sketch the curves of the particular solutions that correspond to each of these initial conditions: \[ y(0) = 1 \qquad\qquad y(-3) = 0 \qquad\qquad y(2) = -1\,.\]
  2. Consider the differential equation \(\dot y = \frac{1}{4}t^2+\frac{1}{4}y^2-3\,.\)
    1. Sketch a direction field for this differential equation for \({-6 \lt y \lt 6}\) and \({-6 \lt t \lt 6\,.}\)
    2. Using your direction field, sketch the curves of the particular solutions that correspond to each of these initial conditions: \[ y(0) = 0 \qquad\qquad y(0) = 3 \qquad\qquad y(3) = 3\,.\]