Thinking about transformations, most basic functions can be thought of in the following forms where the lower case letters 'a' through 'd' have the same meaning. y=a(bx-c)+d, y=asin (bx-c)+d, yasin (bx-c)+d. y=ae (x-c)+d Match each of the lowercase letters with their role. a b d I. left/right shift II. horizontal compression/stretch III. vertical compression/stretch IV. up/down shift