3. Stretches and Compressions:
The role of parameter a:
Examples
a > 1 the graph of ƒ(x) is stretched vertically.
0 < |a| < 1 the graph of ƒ(x) is compressed
vertically.
- the y-coordinates of ƒ are multiplied by a.
The role of parameter b:
b > 1 the graph of ƒ(x) is compressed
horizontally.
(Everything quot;speeds upquot;)
0<|b|<1 the graph of ƒ(x) is stretched
horizontally. (Everything quot;slows downquot;)
- the x-coordinates are multiplied by .
4. Putting it all together ...
Try these examples ... y = ƒ(x)
REMEMBER: stretches
before translations
Don't Look Behind Here
Really!
Are you sure you
want to do this?
5.
6. Practice what you've learned ...
The coordinates of a point, A, on the graph of y = ƒ(x) are (-2, -3). What are
the coordinates of it's image on each of the following graphs:
The image of point B after each transformation shown above is given
below as point C(n). Find the original coordinates of B.
C3 (5, -4) C4 (-1, 6)
C2 (-3, 7)
C1 (2, 3) C5 (-4, -2)
7. Consider the equation below. Which transformation do you think should be
applied first? second? third? fourth?