Question

Исключите переменную а из системы
$displaystyle left { {{x=sin alpha+cos alpha} atop {y=sin alphacdotcos alpha}} right.$

Answer 1

x²=sin²a+cos²a+2sinacosa
x²=1+2sinacosa
sinacosa=(x²-1)/2
y=(x²-1)/2
2y=x²-1
x²=2y+1

Answer 2

$left { {{x=sina+cosa} atop {y=sinacdot cosa}} right. left { {{x^2=sin^2a+2sinacdot cosa+cos^2a} atop {2y=2sinacdot cosa}} right. ; left { {{x^2=1+2sinacdot cosa} atop {2y=2sinacdot cosa} right. ; to \\x^2=1+2y$