Пусть x,y,z>−1x, y, z > -1x,y,z>−1. Докажите неравенство 1+x21+y+z2+1+y21+z+x2+1+z21+x+y2≥2.\dfrac{1+x^2}{1+y+z^2} + \dfrac{1+y^2}{1+z+x^2} + \dfrac{1+z^2}{1+x+y^2} \geq 2. 1+y+z21+x2+1+z+x21+y2+1+x+y21+z2≥2.