### Transformations: Tutorial

#### Select all the correct answers.

Annie transforms the graph of [tex]y = 2^x[/tex] into the graph of [tex]y = 2^x - 4[/tex]. Which statements correctly describe this transformation?

A. It is the graph of [tex]y = 2^x[/tex] translated 4 units to the right.
B. It is the graph of [tex]y = 2^x[/tex] translated 4 units downward.
C. It is the graph of [tex]y = 2^x[/tex] translated 4 units upward.
D. It is the graph of [tex]y = 2^x[/tex] translated 2 units to the right.
E. It is the graph of [tex]y = 2^x[/tex] compressed horizontally 4 units to the left.
F. It is the graph of [tex]y = 2^x[/tex] stretched vertically 2 units upward.



Answer :

To transform the graph of [tex]\( y = 2x \)[/tex] into [tex]\( y = 2x - 4 \)[/tex], we need to understand how the functions differ.

The original equation is:
[tex]\[ y = 2x \][/tex]

The transformed equation is:
[tex]\[ y = 2x - 4 \][/tex]

Here, we can see that the new equation has a term [tex]\(-4\)[/tex] subtracted from the original equation [tex]\( y = 2x \)[/tex]. This term [tex]\(-4\)[/tex] indicates a vertical transformation.

### Identifying the Transformation:

Subtracting 4 from a function [tex]\( y \)[/tex] translates the function graph downward by 4 units. This is because each value of [tex]\( y \)[/tex] in [tex]\( y = 2x \)[/tex] is decreased by 4 units, resulting in [tex]\( y = 2x - 4 \)[/tex].

Thus, the correct statement that describes this transformation is:
- "It is the graph of [tex]\( y=2x \)[/tex] translated 4 units downward."

The other options are incorrect because:
- Translating 4 units to the right would involve modifying the x term, such as in [tex]\( y = 2(x - 4) \)[/tex].
- Translating 4 units upward would involve adding 4 instead of subtracting, resulting in [tex]\( y = 2x + 4 \)[/tex].
- Translating 2 units to the right does not match with -4 units shift in y-coordinates.
- Compressing or stretching horizontally/vertically implies a change in the coefficient of x or y, which is not the case here.

So, we select:
- "It is the graph of [tex]\( y = 2x \)[/tex] translated 4 units downward." as the correct answer.