F(x)=x^3+2x^2-1
Найти f(0) f(1) f(-3) f(5)

  f(x)=x^4/4+2x^3/3-0  =>f(x)=x^4/4+2/3x^3
  f(0)= 0  f(1)=1/4+2/3=(3+8)/12=11/12  f(-3)=81/4-2/3*27=81-18=63  f(5)=5^4/4+2/3*5^3