Exercise 1 | Wiskunde op Tilburg University

Determine all stationary points of

$y(x)=-x^2+6x+7$ .

Antwoord 1 correct

Correct

Antwoord 2 optie

$x=-1$ and

$x=7$

Antwoord 2 correct

Fout

Antwoord 3 optie

$x=6\frac{1}{2}$

Antwoord 3 correct

Fout

Antwoord 4 optie

$y(x)$ has no stationary points.

Antwoord 4 correct

Fout

Antwoord 1 optie

$x=3$

Antwoord 1 feedback

Correct:

$y'(x)=-2x+6$ . Hence,

$y'(x)=0$ gives

$x=3$ . Therefore,

$x=3$ is the unique stationary point of

$y(x)$ .

Go on.

Antwoord 2 feedback

Wrong: A stationary point

$c$ is not a point such that

$y(c)=0$ .

See Stationary point.

Antwoord 3 feedback

Wrong:

$y'(x)\neq -2x+6+7$ .

See Derivative.

Antwoord 4 feedback

Wrong:

$y(x)$ does have a stationary point.

See Example.