Question

Which statement best describes the effect on the graph of y = (x – 9)2 if the equation is changed to y = (x + 9)2? The graph moves up 18 units. The graph moves down 18 units. The graph moves left 18 units. The graph moves right 18 units.

Answer 1

Answer:

Third option: The graph moves left 18 units.

Step-by-step explanation:

Some transformations for a function f(x) are shown below:

If $f(x)+k$, the function is shifted up "k" units.

If $f(x)-k$, the function is shifted down "k" units.

If $f(x+k)$, the function is shifted left "k" units.

If $f(x-k)$, the function is shifted right "k" units.

In this case, we can observe that graph of $y = (x - 9)^2$ is changed to $y = (x + 9)^2$

Since:

 $-9+18=9$

We can conclude that the function $y = (x - 9)^2$ is shifted left 18 units to get the function $y = (x + 9)^2$.

Answer 2

Answer:

The graph moves left 18 units.

Step-by-step explanation: