Answer:
[tex]B. y=x^2+3 \\\\D.$ $x^2+3y=8[/tex]
Step-by-step explanation:
A quadratic function is a function in which the highest power of the unknown variable is 2.
Formally, a quadratic function is defined as a function of the form:
[tex]f(x)=ax^2+bx+c, a\neq 0[/tex]
From the given options, only B and D has the highest power as 2. Therefore, the equations that represent quadratic functions are:
[tex]B. y=x^2+3 \\\\D.$ $x^2+3y=8[/tex]