I wish I had a little cheat-sheet like this during my math classes:
Given vertical translation
a (+ to shift up, - to shift down), vertical scaling
b (larger to grow, smaller to shrink), horizontal translation
c (+ to shift right, - to shift left), and horizontal scaling
d (larger to grow, smaller to shrink), the function transformation would be:
(f((x-c)/d)+a)/b
You can pick and choose values. If you don't have
a or
c, replace with 0. If you don't have
b or
d, replace with 1.
Assume our function f was the sine function.
sin(x):
Say we wanted to shift the whole function to the right by +1, i.e. up the x-axis. c=1 and our transformation would be
sin(x - [+1]):
Note how the graph used to cross the x-axis at 0 (red), but now crosses it at 1 (green).
Say we now wanted to stretch it longer, i.e. horizontally scale it. Maybe stretch it twice as long. If we choose a horizontal scaling factor of d=2, our new function would be
sin((x-1)/2):
Now perhaps we want to shift it upwards, e.g. a=1. Our new function is
sin((x-1)/2)+1:
And finally, we want to stretch our function in the vertical axis, perhaps also by double, so b=2.
(sin((x-1)/2)+1)*2:
Before, it ranged from a minimum y of 0 to a maximum y of 2, now the maximum y is 4.