Question

Решите систему уравнений: cosxsiny=√2/2 x+y=3pi/4

Answer 1

$cos(x)sin(y)= \frac{ \sqrt{2} }{2}\\x+y= \frac{3 \pi }{4} \\y=\frac{3 \pi }{4} -x\\cos(x)sin(\frac{3 \pi }{4} -x)= \frac{ \sqrt{2} }{2}\\cos(x)(sin(\frac{3 \pi }{4})cos(x)-sin(x)cos(\frac{3 \pi }{4}))=\frac{ \sqrt{2} }{2}\\cos(x)(\frac{ \sqrt{2} }{2}cos(x)+\frac{ \sqrt{2} }{2}sin(x))=\frac{ \sqrt{2} }{2}\\cos(x)(cos(x)+sin(x))=1\\cos^2(x)+cos(x)sin(x)-1=0\\cos(x)sin(x)-sin^2(x)=0\\sin(x)(cos(x)-sin(x))=0\\1)sin(x)=0\\x_1= \pi n; y_1= \frac{3 \pi }{4}- \pi n\\2)cox(x)-sin(x)=0\\ tg(x)=1$
$x_2= \frac{ \pi }{4} + \pi n;y_2= \frac{ \pi }{2} - \pi n$