Exercise 1 | Wiskunde op Tilburg University

Consider the function

$y(x) = 2^x$ . Determine the average change of the function value if

$x$ increases from

$x=5$ to

$x=11$ ?

Antwoord 1 correct

Correct

Antwoord 2 optie

$-336$ .

Antwoord 2 correct

Fout

Antwoord 3 optie

$5\tfrac{1}{3}$ .

Antwoord 3 correct

Fout

Antwoord 4 optie

$183\tfrac{3}{11}$ .

Antwoord 4 correct

Fout

Antwoord 1 optie

$336$ .

Antwoord 1 feedback

Correct: The difference quotient is

$\dfrac{\Delta y}{\Delta x} = \dfrac{y(11)-y(5)}{6} = \dfrac{2048-32}{6} = 336$ .

Go on.

Antwoord 2 feedback

Wrong: Pay attention to the order of

$y(x)$ and

$y(x+\Delta x)$ in de nominator or check how you determined

$\Delta x$ .

See also Example 1.

Antwoord 3 feedback

Wrong:

$x+\Delta x \neq 6$ , but

$x+\Delta x = 5+6 = 11$ .

See also Example 1.

Antwoord 4 feedback

Wrong: The increase of

$x$ is

$\Delta x = 11-5 = 6 \neq 11$ .

See also Example 1.