2 câu trả lời
$y=cot(x-\frac{\pi}{5})$
ĐK: $cos(x-\frac{\pi}{5})\neq 0$
$\Leftrightarrow x-\frac{\pi}{5} \neq \frac{\pi}{2}+k\pi$
$\Leftrightarrow x \neq \frac{7\pi}{10}+k\pi,k \in \mathbb{Z}$
TXĐ: $D=R$\$\left \{ \frac{7\pi}{10}+k\pi,k \in \mathbb{Z} \right \}$
Đáp án:
x#7$\pi$/10+k.$\pi$
Giải thích các bước giải:
y=cot (x - $\pi$/5)=$\frac{sin(x-$\pi$/5)}{cos(x-$\pi$/5)}$
ĐKXĐ: cos(x-$\pi$/5)#0
⇔x-$\pi$/5#$\pi$/2+k.$\pi$
⇔x#7$\pi$/10+k.$\pi$
