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Example 4

Find the general solution of the equation

y' + y cos t = t.

Step 1

From Example 1 in Section 14.2, the corresponding homogeneous equation has the particular solution

x = e-sin t.

Step 2

The function v(t) is expressed by an integral.

14_differential_equations-77.gif

We cannot evaluate the integral, so we leave it in this form. It does not matter which value is chosen for the lower endpoint in the integral, so we take the lower endpoint zero.

Step 3

The general solution is y - vx + Cx,

or 14_differential_equations-78.gif

14_differential_equations-79.gif


Last Update: 2006-11-17