Determining if a Function Is Homogeneous In Exercises $69-76,$ determine whether the function is
homogeneous, and if it is, determine its degree. A function $f(x, y)$ is homogeneous of degree $n$ if $f(x, t y)=t^{n} f(x, y) .$
$$f(x, y)=x^{4}+2 x^{2} y^{2}+x+y$$