Question

Tìm x để các căn thức có nghĩa :

a,\(\sqrt{\dfrac{-3}{3-2x}}\)

b,\(\sqrt{\dfrac{\sqrt{x}+2}{\sqrt{x-1}}}\)

c,\(\sqrt{\dfrac{3-x}{\sqrt{x-1}}}\)

d,\(\sqrt{\dfrac{3-x}{\sqrt{x}-1}}\)

 

Answer 1

a: ĐKXĐ: -3/(3-2x)>=0

=>3-2x<0

=>2x>3

hay x>3/2

b: ĐKXĐ: \(\left\{{}\begin{matrix}x-1>0\\x>0\\\sqrt{x-1}>0\end{matrix}\right.\Leftrightarrow x>1\)

c: ĐKXĐ: \(\left\{{}\begin{matrix}\dfrac{3-x}{\sqrt{x-1}}>0\\x-1>0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x>1\\x< 3\end{matrix}\right.\Leftrightarrow1< x< 3\)