How did they change the graph of
y = f(x)
by making it:
y = 2f(x + 8) - 7
First
1. They replaced x by x+8, which shifted the graph 8 units LEFT. That gave:
y = f(x + 8)
then
2. They multiplied the right side by a factor of 2, which STRETCHED the graph
vertically by a factor of 2. That gave:
y = 2f(x + 8)
then
3. They subtracted 7 from the right side, which SHIFTED the graph DOWN by
7 units. That gave
y = 2f(x + 8) - 7
So the correct choice was the middle one:
Shift left 8 units, stretch vertically by a factor of 2, then shift down
7 units.
---------------------------
How did they change the graph of
y = f(x)
by making it
y = 2f(x - 8) + 7
First
1. They replaced x by x-8, which shifted the graph 8 units RIGHT.
That gave:
y = f(x - 8)
then
2. They multiplied the right side by a factor of 2, which STRETCHED
the graph vertically by a factor of 2. That gave:
y = 2f(x - 8)
then
3. They added 7 to the right side, which SHIFTED the graph UP by
7 units. That gave
y = 2f(x - 8) + 7
So the correct choice was the middle one:
Shift right 8 units, stretch vertically by a factor of 2, then shift up
7 units.
---------------------------
Edwin