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Differential Equations                                        Quiz #1                                             February 14, 2005

Name____________________                   R.  Hammack                                                 Score ______
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(1)     The first column in the table contains three differential equations. For each equation, determine whether it's linear, and what its order is.

 Differential Equation Linear? (Yes/No) Order NO 2 YES 3 NO 3

(2)  Consider the differential equation -y=0
For parts (a), (b), (c) and (d) decide if the given function is a solution.

(a)   y=
y'' = 2
Plugging this information into the equation gives

So YES, this is a solution.

(b)   y=-
y'=2x+
y''=2-

Plugging this information into the equation gives

So YES, this is a solution.

(c)   y=
y'=3
y''=6x

Plugging this information into the equation gives

NO, this is not a solution, because the function 4x does not equal the function 0.

(d)  y=0
Plugging this information into the equation gives

So YES, this is a solution