Question

Two students, A and B, claim the following:

A: $y=x^2$ is a linear function.
B: $y=2x-1$ is a linear function.

Choose the correct option.

• A. Neither A nor B is correct.
• B. Both A and B are correct.
• C. Only A is correct.
• D. Only B is correct.

Answer 1

The correct option is D Only B is correct.

$\underset{–}{y=x^2}$

$x$	$y=x^2$
3	9
2	4
1	1
0	0
-1	1
-2	4
-3	9

The graph of $y=x^2$ is not a straight line and, hence, is not a linear function.
$\therefore$ A is incorrect.

$\underset{–}{y=2x-1}$

$x$	$y=2x-1$
2	3
1	1
0	-1
-1	-3
-2	-5

The graph of $y=2x-1$ is a straight line and is a linear function.
$\therefore$ B is correct.

$\therefore$ The correct option is "Only B is correct".