Solve 3−xx−1≥x+4, (x>1).
Antwoord 1 correct
Correct
Antwoord 2 optie
−2−√11≤x≤−2+√11
Antwoord 2 correct
Fout
Antwoord 3 optie
x>1
Antwoord 3 correct
Fout
Antwoord 4 optie
−2−√11≤x<1
Antwoord 4 correct
Fout
Antwoord 1 optie
1<x≤−2+√11
Antwoord 1 feedback
Correct: 3−xx−1≥x+4, where x>1⇔3−xx−1−4−x≥0.
We define f(x)=3−xx−1−4−x and solve f(x)=0:
3−xx−1−4−x=0⇔3−x+(x−1)(−x−4)=0⇔−x2−4x+7=0⇔x2+4x−7=0⇔x=−2−√11 or x=−2+√11.
Note that x=−2−√11 is outside the domain. Via a sign chart we find f(x)≥0 if 1<x≤−2+√11.
Go on.
Antwoord 2 feedback
Wrong: Consider the domain of the function.
Try again.
Antwoord 3 feedback
Wrong: Determine the points of intersection.
See Example 2 (film).
Antwoord 4 feedback
Wrong: Consider the domain of the function.
Try again.