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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.

Please show your work.

(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