Question

решите уравнение плииз​

Answer 1

$1)Ctg(frac{pi }{5}-x)+1=0\\Ctg(frac{pi }{5}-x)=-1\\frac{pi }{5}-x=frac{3pi }{4}+pi n,nin z\\-x=frac{3pi }{4}-frac{pi }{5}+pi n,nin z\\-x=frac{11pi }{20}+pi n,nin z\\x=-frac{11pi }{20}+pi n,nin z$

$2)Sin(3x-frac{pi }{4})Cos(3x-frac{pi }{4})=-frac{1}{2}\\frac{1}{2}*(2Sin(3x-frac{pi }{4})Cos(3x-frac{pi }{4}))=-frac{1}{2} \\frac{1}{2}Sin(6x-frac{pi }{2})=-frac{1}{2}\\Sin(6x-frac{pi }{2})=-1\\Sin(frac{pi }{2}-6x)=1\\Cos6x=1\\6x=2pi n,nin z\\x=frac{pi n }{3} ,nin z$