Math Problem Statement

Given the functions f(x) = e^x and g(x) = e^-x: (a) Draw the graphs of f and g in the range -2 ≤ x ≤ 2. (b) Draw the tangents to the graphs of f and g at the point P(0,1) and provide the equations for these tangents.

Solution

The problem presented is as follows:

Given functions: f(x)=exf(x) = e^x and g(x)=exg(x) = e^{-x}

Tasks:

  1. (a) Draw the graphs of f(x)=exf(x) = e^x and g(x)=exg(x) = e^{-x} in the interval 2x2-2 \leq x \leq 2.
  2. (b) Draw the tangents to the graphs of ff and gg at the point P(0,1)P(0,1) and provide the equations for these tangents.

Solution Outline:

Part (a): Drawing the Graphs of f(x)=exf(x) = e^x and g(x)=exg(x) = e^{-x}

The graphs of f(x)=exf(x) = e^x and g(x)=exg(x) = e^{-x} are exponential functions:

  • f(x)=exf(x) = e^x: an increasing exponential function.
  • g(x)=exg(x) = e^{-x}: a decreasing exponential function.

For the interval 2x2-2 \leq x \leq 2, both functions exhibit typical exponential behavior:

  • f(x)f(x) grows as xx increases.
  • g(x)g(x) decreases as xx increases.

Part (b): Tangent Lines at P(0,1)P(0,1)

  1. Finding the Derivative for f(x)f(x): f(x)=exf'(x) = e^x At x=0x = 0, f(0)=e0=1f'(0) = e^0 = 1.

    So, the tangent line to f(x)f(x) at P(0,1)P(0,1) has a slope of 11. The equation of this tangent is: y1=1(x0)    y=x+1y - 1 = 1(x - 0) \implies y = x + 1

  2. Finding the Derivative for g(x)g(x): g(x)=exg'(x) = -e^{-x} At x=0x = 0, g(0)=e0=1g'(0) = -e^0 = -1.

    So, the tangent line to g(x)g(x) at P(0,1)P(0,1) has a slope of 1-1. The equation of this tangent is: y1=1(x0)    y=x+1y - 1 = -1(x - 0) \implies y = -x + 1

Summary:

  • Graphs of f(x)=exf(x) = e^x and g(x)=exg(x) = e^{-x} should be plotted in the interval 2x2-2 \leq x \leq 2.
  • Tangent equations:
    • For f(x)f(x): y=x+1y = x + 1
    • For g(x)g(x): y=x+1y = -x + 1

Would you like assistance with plotting these graphs or further explanation?


Here are 5 related questions to deepen your understanding:

  1. How does the rate of change of an exponential function compare to that of a linear function?
  2. Why does g(x)=exg(x) = e^{-x} have a negative slope at x=0x = 0?
  3. What effect does changing the base of the exponential function (from ee to another base) have on the graph?
  4. How would the tangent lines change if the point were not P(0,1)P(0,1) but a different point on the graph?
  5. How does the symmetry of f(x)=exf(x) = e^x and g(x)=exg(x) = e^{-x} reflect in their respective tangent lines?

Tip: Remember, the slope of the tangent line at a point is given by the derivative evaluated at that point.

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Math Problem Analysis

Mathematical Concepts

Exponential Functions
Tangent Lines
Derivatives

Formulas

f(x) = e^x
g(x) = e^-x
Tangent line equation: y - y1 = m(x - x1)
Derivative of f(x) = e^x is f'(x) = e^x
Derivative of g(x) = e^-x is g'(x) = -e^-x

Theorems

Derivative of Exponential Functions

Suitable Grade Level

Grades 11-12