Pearson Algebra 2 Common Core, 2011
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Pearson Algebra 2 Common Core, 2011 View details
2. Properties of Exponential Functions
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Exercise 34 Page 448

How do you think the graph will change if c>1?

See solution.

Practice makes perfect

We want to show how the graph of the function y changes depending on c when a is positive and b≥ 1. y= a b^(cx) We will examine the effects of c in three cases.

When c>0

The effects of c, greater than zero, should be analyzed in three parts.

  • If 0< c<1 , the function grows slowly compared to the parent function of exponential functions. That is, the parent function is stretched horizontally.
  • If c= 1, we get the function y=ab^x.

y=ab^(1* x) ⇒ y=ab^x

  • If c>1, the function grows quickly compared to the parent function of exponential functions. That is, the parent function is compressed horizontally.

When c=0

The graph will be a constant function since the exponent will be zero. y=ab^(0* x) ⇔ y=ab^0 By the Zero Exponent Rule, b^0=1, so the function becomes y=a. y=a* 1 ⇔ y=a

When c<0

For the values of c less than 0, the function becomes a decreasing function and the graph is reflected across the y-axis. Let's organize what we have said so far.

y=ab^(cx)
c - Orientation and Shape
If 0<|c|<1, the graph is stretched horizontally If |c|>1, the graph is compressed horizontally
If c=0, the graph is equal to y=a If |c|=1, the graph is equal to y=ab^x
If c<0, the graph is reflected across the y-axis

Consider the table above and examine the changes on the graph of the function for the different c-values.