Section 3.1 Exponential Functions
Definition An exponential function is in the form where and
The Graph of an Exponential Function There are two cases to consider when graphing an exponential function: Case I: a >1 Case II: 0 < a < 1
Case I: a > 1 The domain is and the range is The y-intercept is (0,1) The graph has a horizontal asymptote y = 0
Using Your Graphing Calculator
Case II: 0 < a < 1 The domain is and the range is The y-intercept is (0,1) The graph has a horizontal asymptote y = 0
Using Your Graphing Calculator
Transformations of Exponential Function Graphs All the standard rules apply. “inside” occurs at the exponent level. “outside” occurs at the base level. When possible, use your graphing calculator to help with the transformations. When you shift a graph vertically, the horizontal asymptote also shifts the same number of units and in the same direction. The range also changes as a result of a vertical shift.
Transformations of f(x) = 2 x
The number e e is an irrational number Your scientific calculator can be used to raise e to various powers.
Investing Money When you invest money, what are the factors that determine the return on your investment? 1.The amount you invest (P) 2.The interest rate (r) 3.The length of the investment (t) 4.The number of times per year you earn interest on the investment (n)
Two Formulas
Compounding Table Type of compoundingn Annually1 Semi-annually2 Quarterly4 Monthly12 Weekly52 Daily365 ContinuouslyUse “pert”
Example Suppose we are investing $5000 for 7 years at a rate of 6%. Find the amount in the account at the end of the investment period if interest in compounded: 1.Annually 2.Quarterly 3.Weekly 4.Continuously