Question

giải pt: sin ( 2x + 35 độ) = -√2/3

Answer 1

\(\Leftrightarrow\left[{}\begin{matrix}2x+35^0=arcsin\left(-\dfrac{\sqrt{2}}{3}\right)+k360^0\\2x+35^0=180^0-arcsin\left(-\dfrac{\sqrt{2}}{3}\right)+k360^0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=17,5^0+\dfrac{1}{2}arcsin\left(-\dfrac{\sqrt{2}}{3}\right)+k180^0\\x=72,5^0-\dfrac{1}{2}arcsin\left(-\dfrac{\sqrt{2}}{3}\right)+k180^0\end{matrix}\right.\) (\(k\in Z\))

Answer 2

Đề là \(-\dfrac{\sqrt{2}}{3}\) hay \(-\dfrac{\sqrt{3}}{2}\)?

\(-\dfrac{\sqrt{2}}{3}\) thì kết quả sẽ rất xấu