In Problems 21 and 22, first use the method of Example 2 to construct a slope field for the given differential equation. Then sketch the solution curve corresponding to the given initial condition. Finally, use this solution curve to estimate the desired value of the solution y(x).

y' = x + y, y(0) = 0; y(-4) = ?

Example 2

Example 2 Construct a slope field for the differential equation y'=x-y and use it to sketch an approx- imate solution curve that passes through the point (-4,4).