Example of quotient rule : Let's now see example on quotient rule.  In this, unlike the product rule examples, some of these functions will require the quotient rule to get the derivative. However the last two, we can ignore the quotient rule if we'd like to as we'll see.

Example   Differentiate following functions.

                       W ( z ) = 3z + 9 /2 - z

Solution

There isn't a lot to do here other than to use the quotient rule.  Following is the work for this function.

W ′ ( z ) = 3( 2 - z )- (3z + 9) ( -1) / (2 - z )²

               =15 /(2 - z )²