Let f x 3 Then the expression can be written in the form A Bx Ch 3 Dx 3 where A B C and D are constants Note It s possible for one or more of these constants to be 0 Find the constants A B C D Use your answer from above to find lim h 0 lim h 0 f x h f x h Finally find each of the following f 1 f 2 3 f x h f x h f x h f x h