Question

Graphing transformations, how is the f function affected?. question.
y = - 2f (x+1) +1

Answer 1

Okay, it moves 1 unit to the left for x unit (subtract 1) and up one y-unit (add 1). What does the -2 in front of the f function do?

Answer 2

The 2 is a scaling factor,
it doubles the output,
so the function is stretched vertically by a factor of 2.

The negative reflects the function across the x-axis.

Answer 3

@zepdrix so doing it algebraically, I would multiply the y unit by 2?

Answer 4

You mean to get your new y value from the previous f?
You would do these transformations, `in this order`:
Shift it 1 left,
Reflect it across the x-axis,
Multiply it by 2,
Shift it 1 up

The reason I'm making a point about the order is because
notice that the negative sign is not being applied to the +1 on the end.

Answer 5

So shift 1 x-unit left, shift 1 y-unit up, and multiply 2 to what? both x and y?

Answer 6

to get the new function

Answer 7

this is for when I am plotting points for the new function

Answer 8

Ahh sorry.

Shift 1 left (Decrease x by 1)
Reflect it across the x-axis (y value becomes negative)
Multiply by 2 (Multiply y value by 2)
Shift 1 up (Increase y by 1)

Every transformation is applied to y,
except for the left/right shift.

Let's take one arbitrary point, such as (2,5).
Shift 1 left (1,5)
Reflect (1,-5)
Multiply by 2 (1,-10)
Shift 1 up (1,-9)

We started at (2,5) and our transformation took us to (1,-9).

Answer 9

Okay, I see it not with your explanation. Graphing is my weakest area, so I'm reviewing graphing concepts. Thanks! :)

Answer 10

not=now*

Answer 11

np!