Question

2^4 + 3x^2y^2 + y^2 + y^4, если x^2 + y^2 = 1
1) 3
2) 5
3) 2
4) 1

Answer 1

$2x^4+3x^2y^2+y^2+y^4\ x^2+y^2=1 \\ x^2=1-y^2\ 2(1-y^2)^2+3*(1-y^2)y^2+y^2+y^4 = \ 2(1-2y^2+y^4)+3y^2-3y^4+y^2+y^4=\ 2-4y^2+2y^4+3y^2-3y^4+y^2+y^4=2$

Ответ 2