Pearson Algebra 2 Common Core, 2011
PA
Pearson Algebra 2 Common Core, 2011 View details
2. Properties of Exponential Functions
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Exercise 33 Page 448

Recall the possible transformation of exponential functions of the form f(x)=ab^(x-h)+k.

The graph of the given function is a shift of the parent function 2 units to the left and 1 unit up.

Practice makes perfect

Let's first recall all possible transformations of exponential functions.

f(x)=ab^(x-h)+k
h - Horizontal Translation

h units right if h is positive
|h| units left if h is negative

k - Vertical Translation

k units up if k is positive
|k| units down if k is negative

a - Orientation and Shape
If a<0, the graph is reflected across the x-axis If |a|>1, the graph is stretched vertically

If 0<|a|<1, the graph is compressed vertically

We need to identify the values of a, h, and k for the given function. f(x)=(1/3)^(x+2)+1 ⇕ f(x)= 1 (1/3)^(x-( - 2))+ 1 We see above that a= 1, h= - 2, and k= 1. Using the table of transformations, we can determine if the parent graph is translated vertically or horizontally.

  • h= - 2, the parent function is translated two units to the left.
  • k= 1, the parent function is translated one unit up.

The student thinks that subtracting a negative or a positive number from the exponent shifts the parent graph vertically and that adding a negative or a positive number to parent function shifts the graph horizontally. However, it should be the other way around.