Question

[Nguyệt Minh]

Chi tiết giùm mình nhé, gấp lắm ạ!

Answer 1

[Hồng Phúc]

1.

\(\left(sinx+1\right)\left(sinx-\sqrt{2}\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}sinx=-1\\sinx=\sqrt{2}\left(l\right)\end{matrix}\right.\)

\(\Leftrightarrow sinx=-1\)

\(\Leftrightarrow x=-\dfrac{\pi}{2}+k2\pi\)

2.

\(sin2x\left(2sinx-\sqrt{2}\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}sin2x=0\\2sinx-\sqrt{2}=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}sin2x=0\\sinx=\dfrac{\sqrt{2}}{2}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{k\pi}{2}\\x=\dfrac{\pi}{4}+k2\pi\\x=\dfrac{3\pi}{4}+k2\pi\end{matrix}\right.\)