Composite functions
Graph the composition of two functions Compute specific value of the composition of two functions

Graph the composition of two functions

Suppose you want to graph \( (f \circ g)(x) \) for the following functions:

\[ f(x) = x^2 - 2x + 5, \quad g(x) = \frac{x + 3}{4} \]

  1. Create a new document, press Doc Icon, and select Add Calculator.
  2. Enter the two expressions \( f(x) \) and \( g(x) \), each on a different line:
    • Write f(x) and press Enter Icon Enter Icon.
    • Do the same for \( g(x) \).
  3. Write f(g(x)) in a third line and press Enter Icon. The result is displayed.

    Recursive Formula Example

  4. To plot the function, open a new page by pressing Ctrl Icon and Doc Icon. Select Add Graphs.
  5. Write f1(x) = f(g(x)) and press Enter Icon.
  6. Choose an appropriate window. Press Menu Icon and select Window/Zoom > Window Settings. Enter the appropriate values: \[ X_{\text{min}} = -30, \quad X_{\text{max}} = 30, \quad Y_{\text{min}} = -100, \quad Y_{\text{max}} = 100 \]

    Recursive Formula Example

Compute specific value of the composition of two functions

Suppose you want to evaluate \( (f \circ g)(1) \) for the following functions:

\[ f(x) = x^2 - 2x + 5, \quad g(x) = \frac{x + 3}{4} \]

  1. Create a new document, press Menu Icon, and select Add Calculator.
  2. Enter the two expressions \( f(x) \) and \( g(x) \), each on a different line:
    • Write f(x) and press Ctrl Icon and >System Icon.
    • Do the same for \( g(x) \).
  3. Write f(g(1)) in a third line and press Enter Icon. The result is displayed.

    Graph Composition Screenshot

    The result should be \( 4 \). Thus, \( (f \circ g)(1) = 4 \).