Question

Cho hàm số y = f(x) = x² – 1 . Tìm x sao cho f(x) = 1 .

 

Answer 1

\(f\left(x\right)=x^2-1\)

\(\Rightarrow f\left(x\right)=1\Leftrightarrow x^2-1=1\)

\(\Leftrightarrow x^2=2\)

\(\Leftrightarrow x=\sqrt{2}\) hoặc \(x=-\sqrt{2}\)

Answer 2

y=f(x)=x²-1

\(\Rightarrow\)f(1)=1²-1=0

Answer 3

ta có: f(x)=1 => x² -1 = 1

x² = 1+1=2 => x= \(\sqrt{2}\)

Vậy x=\(\sqrt{2}\)