Question

Answer 1

b: Tọa độ giao điểm là:

\(\left\{{}\begin{matrix}2x^2-x-1=0\\y=x+1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\left(x-1\right)\left(2x+1\right)=0\\y=x+1\end{matrix}\right.\Leftrightarrow\left(x,y\right)\in\left\{\left(1;2\right);\left(-\dfrac{1}{2};\dfrac{1}{2}\right)\right\}\)

c: \(2x^2-x-1< 0\)

=>(x-1)(2x+1)<0

=>-1/2<x<1