Which function is a quadratic function? t(x)=(x-4)^2+3 q(x)=(2x+4)^3+3 C r(x)=(-6x-4)^4+3(x+2)^2 s(x)=-(x-6)+3(x+1)

The correct answer is A: $t(x)=(x-4)^{2}+3$.<br /><br />A quadratic function is a function of the form $f(x)=ax^{2}+bx+c$, where $a$, $b$, and $c$ are constants and $a\neq 0$. In this case, $t(x)=(x-4)^{2}+3$ is a quadratic function because it can be written in the form $f(x)=ax^{2}+bx+c$ with $a=1$, $b=-8$, and $c=19$.<br /><br />The other options are not quadratic functions:<br /><br />B: $q(x)=(2x+4)^{3}+3$ is a cubic function.<br />C: $r(x)=(-6x-4)^{4}+3(x+2)^{2}$ is a quartic function.<br />D: $s(x)=-(x-6)+3(x+1)$ is a linear function.