Question

Which of the following algebraic expressions/equations can represent a function?

• A. $a{x}^2+bx+c$
• B. $y=x^2+7$
• C. $y^2=x$
• D. $y=2x-3$

Answer 1

Answer: (A), (B), (D)

The correct options are
A $a{x}^2+bx+c$
B $y=x^2+7$
D $y=2x-3$

$a{x}^2+bx+c$ can represent a function.
$y=x^2+7$ can represent a function.
$y=2x-3$ can represent a function.

Only $y^2=x$ cannot represent a function because for every positive of x, y will take 2 values.
For example: when x = 4 $⟹$ y = −2 or y = +2