Question

Tìm x:

a.\(\left(x-\dfrac{1}{2}\right)^2=\dfrac{1}{8}\)

Answer 1

\(\left(x-\dfrac{1}{2}\right)^2=\dfrac{1}{8}\Rightarrow\left[{}\begin{matrix}x-\dfrac{1}{2}=\sqrt{\dfrac{1}{8}}\\x-\dfrac{1}{2}=-\sqrt{\dfrac{1}{8}}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{2+\sqrt{2}}{4}\\x=\dfrac{2-\sqrt{2}}{4}\end{matrix}\right.\)

Vậy \(\left[{}\begin{matrix}x=\dfrac{2+\sqrt{2}}{4}\\x=\dfrac{2-\sqrt{2}}{4}\end{matrix}\right.\)

Answer 2

a, \(\left(x-\dfrac{1}{2}\right)^2=\dfrac{1}{8}\)

=> \(x^2-\dfrac{1}{2}=\dfrac{1}{8}\)

=> \(x^2=\dfrac{5}{8}\)

=> \(x=\pm\sqrt{\dfrac{5}{8}}\)