Select the correct answer.

Each statement describes a transformation of the graph of [tex]$y = x$[/tex]. Which statement correctly describes the graph of [tex]$y = x - 8$[/tex]?

A. It is the graph of [tex][tex]$y = x$[/tex][/tex] translated 8 units up.
B. It is the graph of [tex]$y = x$[/tex] where the slope is decreased by 8.
C. It is the graph of [tex]$y = x$[/tex] translated 8 units down.
D. It is the graph of [tex][tex]$y = x$[/tex][/tex] translated 8 units to the left.



Answer :

Let's analyze the transformation given in the options step-by-step:

1. Understanding the Original Graph [tex]\( y = x \)[/tex]:
- This is a straight line with a slope of 1, passing through the origin (0, 0).

2. Analyzing the Transformation [tex]\( y = x - 8 \)[/tex]:
- This equation can be interpreted as taking the graph of [tex]\( y = x \)[/tex] and applying a vertical translation.
- Here, the subtraction of 8 affects the [tex]\( y \)[/tex]-value at every point on the line [tex]\( y = x \)[/tex].

Let's go through each option to see which one correctly describes this transformation:

A. It is the graph of [tex]\( y = x \)[/tex] translated 8 units up:
- If we translate [tex]\( y = x \)[/tex] 8 units up, the equation would be [tex]\( y = x + 8 \)[/tex].
- This is not correct, as our transformation involves subtracting 8, not adding.

B. It is the graph of [tex]\( y = x \)[/tex] where the slope is decreased by 8:
- The equation [tex]\( y = x - 8 \)[/tex] does not change the slope of the line.
- The slope remains 1; only the y-intercept is affected.
- Hence, this option is incorrect.

C. It is the graph of [tex]\( y = x \)[/tex] translated 8 units down:
- Translating a graph downwards means subtracting a value from the [tex]\( y \)[/tex]-values.
- The equation [tex]\( y = x - 8 \)[/tex] represents the graph of [tex]\( y = x \)[/tex] translated 8 units down.
- This matches our transformation perfectly.

D. It is the graph of [tex]\( y = x \)[/tex] translated 8 units to the left:
- Translating the graph to the left involves shifting the [tex]\( x \)[/tex]-values which modifies the equation to [tex]\( y = (x + 8) \)[/tex].
- This does not match our given equation [tex]\( y = x - 8 \)[/tex].

Based on this analysis:

The correct answer is C. It is the graph of [tex]\( y = x \)[/tex] translated 8 units down.