Find the condition which is equivalent to the fact that the equation
\(ax^{2} + bx + c = 0\) with
\(x\in \mathbb{R}\) and real
coefficients \(a\),
\(b\),
\(c\) has
two solutions and one of the solutions is a reciprocal value of the second solution.
Which part of the plane describes the solution of the following system of
inequalities?
\[\begin{aligned}
x +\phantom{ 3}y\leq &3 & &
\\y - 2x < & - 1 & &
\end{aligned}\]
Which part of the plane describes the solution of the following system of
inequalities?
\[\begin{aligned}
x + y > &2 + x & &
\\y + 1\leq &x + 1 & &
\end{aligned}\]
Which part of the plane describes the solution of the following system of
inequalities?
\[\begin{aligned}
2x - y\geq &2 & &
\\2x + y\geq & - 2 & &
\end{aligned}\]