Question

Tìm x để B=\(\dfrac{1}{\sqrt{x-1}}+\dfrac{2}{\sqrt{x^2}-4x+4}\) có nghĩa

 

Answer 1

Để B có nghĩa thì:

\(\left\{{}\begin{matrix}x-1\ge0\\x-1\ne0\\\sqrt{x^2}-4x+4\ne0\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}x>1\\x\ne\dfrac{4}{3}\end{matrix}\right.\)

Answer 2

ĐKXĐ: \(\left\{{}\begin{matrix}x>1\\x\ne2\end{matrix}\right.\)