Question

Which equation does not represent a quadratic function?

Y = (x + 3)^2

y = 3x^2

y = 6x^2 - 1

y = x + 5

Answer 1

$\text{A quadratic function is in the form of } ~ f(x)=ax^2 +bx+c.\\\\\\y=x+5 ~ \text{is linear so it is not in a form of quadratic function.}$