Which of the following functions is a linear function of two variables, and what is the function value in $(x,y)=(1,2)$?
Antwoord 1 correct
Correct
Antwoord 2 optie
$y(x) = 5x+2$; the corresponding function value is 7.
Antwoord 2 correct
Fout
Antwoord 3 optie
$z(x,y) = -x + y$; the corresponding function value is $(1,2)$.
Antwoord 3 correct
Fout
Antwoord 4 optie
$z(x,y) = x^2 + y^2$;the corresponding function value is 10.
Antwoord 4 correct
Fout
Antwoord 1 optie
$z(x,y) = -x + y$; the corresponding function value is 1.
Antwoord 1 feedback
Correct: $z(x,y)=-x+y$ is indeed a linear function of two variables. The function value is $z(1,2)=-1+2=1$.
Go on.
Go on.
Antwoord 2 feedback
Wrong: $y(x)=5x+2$ is a linear function of one variable, not of two.
See Linear functions of two variables.
See Linear functions of two variables.
Antwoord 3 feedback
Wrong: Although $z(x,y)=-x + y$ is a linear function of two variables, the function value is the value of the output variable, not the value of the input variables.
See Functions of two variables.
See Functions of two variables.
Antwoord 4 feedback
Wrong: $z(1,2)=10$ is correct, but $z(x,y) = x^2 + y^2$ is not a linear function.
See Linear functions of two variables.
See Linear functions of two variables.