# 1 a

The Maple commands for differentiation are diff and Diff . Both are used in the same way; the difference is that diff automatically evaluates the derivative while Diff leaves the derivative unevaluated. Here you can see the difference:

> prob1a := Diff( sin( Pi*r ) * exp( -r ), r );

> value( prob1a );

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> diff( sin( Pi*r ) * exp( -r ), r );

In general it is better to use Diff as this allows you to verify that the problem has been entered correctly.

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