f(z)=f(xy)=0 xy=0 T.theodor 2023.4.29.

f(z)=h(xy)/g(xy) T.theodor 2023.4.29.

f(x)=αn+kxn+βn+k+1xn-1…+ω T.theodor 2023.4.29.

f(x)=αnxn+βn-1xn-1…+ω T.theodor 2023.4.29.

Δz/Δy=nα'αnyn-1+(n−1)ββn-1yn-2…+y T.theodor 2023.4.29.

f(z)=αxnyn+βxn-1yn-1…+ω T.theodor 2023.4.29.

f(x) n=2k , ω>0 , +α>r , −α<r' , ω<0 , +α>r , −α<r' , n=2k−1 , ω>0 , +α>r , −α<r' , ω<0 , +α>r , −α</r'></r'></r'>

f(x)→n-gon min S= T.theodor 2023.4.29.