2.2.42

			2.3.4

			2.3.11

			2.3.17

			First derivative depends only on independent variable?

			Variables are separable

			ODEs of the form:  y' = a(t)y + f(t) are called first-order linear ODEs.  They are first-order because the highest derivative is the first derivative.  They are linear because the first derivative depends directly only on y to the first power (not y2 or y1/2 or sin(y) or y-1 or etc.).  Note that the coefficient of the linear term (the one with y) can be any function of t.  That is, a(t) does not need to be linear in t.  It's only the dependent variable that must be linear.  First-order linear ODEs can be solved by finding an integrating factor of the form:

			Read pp. 47-51 of the text.

			Do exercises p. 55 (5, 13, 15, 19, 22, 28).