var('m k y z')
def Tn(m,x):
izraz = sum(binomial(m,2*k)*(x^2-1)^k*x^(m-2*k),k,0,floor(m/2))
return izraz
slika1=implicit_plot3d(Tn(8,x)+Tn(8,y)+Tn(8,z), (x,-1.5,1.5), (y,-1.5,1.5), (z,-1.5,1.5),plot_points=70, color='lemonchiffon')
slika1.show(viewer='threejs',online=True,frame=False)