Which of the following are quadratic functions?

check all that apply.

a. y=2(x-3x^2+1)
b. y=5+2x
c. y=1/2x^2-13x+4
d. y= x/x-1 which of the following are quadratic functions?

check all that apply.

a. y=2(x-3x^2+1)
b. y=5+2x
c. y=1/2x^2-13x+4
d. y= x/x-1