Exercise 1 | Wiskunde op Tilburg University

Consider the revenue function

$R(x)=5x$ and the cost function

$C(x)=2x+21$ . Determine the break-even point.

Antwoord 1 correct

Correct

Antwoord 2 optie

$x=3$

Antwoord 2 correct

Fout

Antwoord 3 optie

$x=63$

Antwoord 3 correct

Fout

Antwoord 4 optie

$x=0$

Antwoord 4 correct

Fout

Antwoord 1 optie

$x=7$

Antwoord 1 feedback

Correct:

$\begin{align*} R(x) = C(x) & \Leftrightarrow 5x=2x+21\\ & \Leftrightarrow 3x=21\\ & \Leftrightarrow x=7. \end{align*}$

Hence, the break-even point is

$x=7$ .

Go on.

Antwoord 2 feedback

Wrong:

$5x=2x+21 \Leftrightarrow 7x=21$ is not correct.

See Linear functions: Example 2.

Antwoord 3 feedback

Wrong:

$3x=21 \Leftrightarrow x=63$ is not correct.

See Linear functions: Example 2.

Antwoord 4 feedback

Wrong: Profit should be zero, not the production level.

See Break-even.