. a. Using S and & , define lim f (x) =L (this is the formal definition) X -> c b. Use your "own words" to define lim f(x) =L (this is the informal definition) X -> c . a. Show lim (3x -7) = -1 by using a 8 -& proof. x->2 b. Determine a number S for & =.0003 such that lim (3x -7) =-1. Use your result from a. to x - 2 help. . Define: derivative of a function f (x) a. Using symbols b. Using "your own words"