[email protected] , ответ добавлен 19.07.2018 в 07:10

(2sinx/2-1)(2sinx/2+1)=0
sinx/2=1/2 U sinx/2=-1/2
x/2=π/6+2πk x/2=5π/6+2πk x/2=-π/6+2πk x/2=-5π/6+2πk
x=π/3+4πk x=5π/3+4πk x=π/3+4πk x=5π/3+4πk ,k∈z

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