[tex]2cos[\frac{\prod }{6}(sinx-13+\frac{\sqrt{2}}{2})]=\sqrt{3}[/tex]
=> cos[\frac{\pi }{6}(sinx-13+\frac{\sqrt{2}}{2})]=\frac{\sqrt{3}}{2}=cos\frac{\pi }{6}
TH1:
=> [TEX]\frac{\pi }{6}(sinx-13+\frac{\sqrt{2}}{2})=\frac{\pi }{6}+k2\pi [/TEX]
=> [TEX]sinx-13+\frac{\sqrt{2}}{2}=1+12k[/TEX]
=> [TEX]sinx=14-\frac{\sqrt{2}}{2}+12k[/TEX]
Vì [tex]-1\leq sinx\leq 1[/tex]
=> [tex]-1\leq 14-\frac{\sqrt{2}}{2}+12k\leq 1[/tex]
Vì k nguyên nên trường hợp này vô nghiệm
TH2:
=> [TEX]\frac{\pi }{6}(sinx-13+\frac{\sqrt{2}}{2})=\frac{-\pi }{6}+k2\pi [/TEX]
=> [TEX]sinx-13+\frac{\sqrt{2}}{2}=-1+12k[/TEX]
=> [TEX]sinx=12-\frac{\sqrt{2}}{2}+12k[/TEX]
Vì [tex]-1\leq sinx\leq 1[/tex]
=> [tex]-1\leq 12-\frac{\sqrt{2}}{2}+12k\leq 1[/tex]
Vì k nguyên => k=-1
=> [TEX]sinx=\frac{\sqrt{2}}{2}[/TEX]
=> ..............