91影视

鈸� $鈭�x^2+2x鈭�4鈮�0$ 鈸�$鈭�x^2+2x鈭�4鈮�0$

Write the quadratic inequality in standard form.

$鈭�x^2+2x鈭�4鈮�0$

Determine the critical points by solving the related quadratic equation.

$-x^2+2x-4=0$

Write the Quadratic Formula., and simplify the radicand

$$\begin{gathered} x=\frac{-b卤\sqrt{b^2-4ac}}{2a} \\ x=\frac{-2卤\sqrt{2^2-4\left(-1路-4\right)}}{2\left(-1\right)} \\ x=1卤\sqrt{3}i \end{gathered}$$

The complex solutions tell us the parabola does not intercept the x-axis.

Also, the parabola opens downward. This tells us that the parabola is completely below the x-axis

Write the quadratic inequality in standard form.

$鈭�x^2+2x鈭�4鈮�0$

Determine the critical points by solving the related quadratic equation

$-x^2+2x-4=0$

Since the corresponding quadratic equation is the same as in part (a), the parabola will be the same.

The parabola opens downward and is completely below the x-axis鈥攏o part of it is above the x-axis.

We are to find the solution to $鈭�x^2+2x鈭�4鈮�0$. Since for all values of x the graph is never above the x-axis, no values of x make the inequality true. There is no solution to the inequality.