Solve x2+8x+1>2x2+2x2.
All x except x=1
x=1
x<1
x>1
Solve x2+8x+1>2x2+2x2.
Antwoord 1 correct
Correct
Antwoord 2 optie
x=1
Antwoord 2 correct
Fout
Antwoord 3 optie
x>1
Antwoord 3 correct
Fout
Antwoord 4 optie
x<1
Antwoord 4 correct
Fout
Antwoord 1 optie
All x except x=1
Antwoord 1 feedback
Correct: x2+8x+1>2x2+2x23x2+6x+3>0.

Define f(x)=3x2+6x+3. We determine f(x)=0:

We use the quadratic equation. The discriminant is D=0, which implies that there is only one solution, x=1.

Via the sign chart (for instance with f(2)=3 and f(0)=3) we find that f(x) is strictly positive for all x expect for the zero x=1.

Go on.
Antwoord 2 feedback
Wrong: (1)2+8(1)+1=66=2(1)2+2(1)2.

Try again.
Antwoord 3 feedback
Wrong: Pay attention to the sign chart.

Try again.
Antwoord 4 feedback
Wrong: Pay attention to the sign chart.

Try again.