Solución detallada
Para cada expresión dentro del módulo en la ecuación
admitimos los casos cuando la expresión correspondiente es ">= 0" o "< 0",
resolvemos las ecuaciones obtenidas.
1.
$$x \geq 0$$
$$x + 2 \geq 0$$
o
$$0 \leq x \wedge x < \infty$$
obtenemos la ecuación
$$a x - \frac{a}{2} - x - \left(x + 2\right) = 0$$
simplificamos, obtenemos
$$a x - \frac{a}{2} - 2 x - 2 = 0$$
la resolución en este intervalo:
$$x_{1} = \frac{a + 4}{2 \left(a - 2\right)}$$
2.
$$x \geq 0$$
$$x + 2 < 0$$
Las desigualdades no se cumplen, hacemos caso omiso
3.
$$x < 0$$
$$x + 2 \geq 0$$
o
$$-2 \leq x \wedge x < 0$$
obtenemos la ecuación
$$a x - \frac{a}{2} - - x - \left(x + 2\right) = 0$$
simplificamos, obtenemos
$$a x - \frac{a}{2} - 2 = 0$$
la resolución en este intervalo:
$$x_{2} = \frac{a + 4}{2 a}$$
4.
$$x < 0$$
$$x + 2 < 0$$
o
$$-\infty < x \wedge x < -2$$
obtenemos la ecuación
$$a x - \frac{a}{2} - - x - \left(- x - 2\right) = 0$$
simplificamos, obtenemos
$$a x - \frac{a}{2} + 2 x + 2 = 0$$
la resolución en este intervalo:
$$x_{3} = \frac{a - 4}{2 \left(a + 2\right)}$$
Entonces la respuesta definitiva es:
$$x_{1} = \frac{a + 4}{2 \left(a - 2\right)}$$
$$x_{2} = \frac{a + 4}{2 a}$$
$$x_{3} = \frac{a - 4}{2 \left(a + 2\right)}$$
//4 + a \ //4 + a \
||----- for And(a <= -4/5, a > -4)| ||----- for And(a <= -4/5, a > -4)|
x1 = I*im|< 2*a | + re|< 2*a |
|| | || |
\\ nan otherwise / \\ nan otherwise /
$$x_{1} = \operatorname{re}{\left(\begin{cases} \frac{a + 4}{2 a} & \text{for}\: a \leq - \frac{4}{5} \wedge a > -4 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a + 4}{2 a} & \text{for}\: a \leq - \frac{4}{5} \wedge a > -4 \\\text{NaN} & \text{otherwise} \end{cases}\right)}$$
// -4 + a \ // -4 + a \
||--------- for And(a > -2, a < -4/5)| ||--------- for And(a > -2, a < -4/5)|
x2 = I*im|<2*(2 + a) | + re|<2*(2 + a) |
|| | || |
\\ nan otherwise / \\ nan otherwise /
$$x_{2} = \operatorname{re}{\left(\begin{cases} \frac{a - 4}{2 \left(a + 2\right)} & \text{for}\: a > -2 \wedge a < - \frac{4}{5} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a - 4}{2 \left(a + 2\right)} & \text{for}\: a > -2 \wedge a < - \frac{4}{5} \\\text{NaN} & \text{otherwise} \end{cases}\right)}$$
// 4 + a 4 + a \ // 4 + a 4 + a \
||---------- for ---------- >= 0| ||---------- for ---------- >= 0|
x3 = I*im|<2*(-2 + a) 2*(-2 + a) | + re|<2*(-2 + a) 2*(-2 + a) |
|| | || |
\\ nan otherwise / \\ nan otherwise /
$$x_{3} = \operatorname{re}{\left(\begin{cases} \frac{a + 4}{2 \left(a - 2\right)} & \text{for}\: \frac{a + 4}{2 \left(a - 2\right)} \geq 0 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a + 4}{2 \left(a - 2\right)} & \text{for}\: \frac{a + 4}{2 \left(a - 2\right)} \geq 0 \\\text{NaN} & \text{otherwise} \end{cases}\right)}$$
x3 = re(Piecewise(((a + 4)/(2*(a - 2), (a + 4)/(2*(a - 2)) >= 0), (nan, True))) + i*im(Piecewise(((a + 4)/(2*(a - 2)), (a + 4)/(2*(a - 2)) >= 0), (nan, True))))
Suma y producto de raíces
[src]
//4 + a \ //4 + a \ // -4 + a \ // -4 + a \ // 4 + a 4 + a \ // 4 + a 4 + a \
||----- for And(a <= -4/5, a > -4)| ||----- for And(a <= -4/5, a > -4)| ||--------- for And(a > -2, a < -4/5)| ||--------- for And(a > -2, a < -4/5)| ||---------- for ---------- >= 0| ||---------- for ---------- >= 0|
I*im|< 2*a | + re|< 2*a | + I*im|<2*(2 + a) | + re|<2*(2 + a) | + I*im|<2*(-2 + a) 2*(-2 + a) | + re|<2*(-2 + a) 2*(-2 + a) |
|| | || | || | || | || | || |
\\ nan otherwise / \\ nan otherwise / \\ nan otherwise / \\ nan otherwise / \\ nan otherwise / \\ nan otherwise /
$$\left(\left(\operatorname{re}{\left(\begin{cases} \frac{a + 4}{2 a} & \text{for}\: a \leq - \frac{4}{5} \wedge a > -4 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a + 4}{2 a} & \text{for}\: a \leq - \frac{4}{5} \wedge a > -4 \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right) + \left(\operatorname{re}{\left(\begin{cases} \frac{a - 4}{2 \left(a + 2\right)} & \text{for}\: a > -2 \wedge a < - \frac{4}{5} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a - 4}{2 \left(a + 2\right)} & \text{for}\: a > -2 \wedge a < - \frac{4}{5} \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right)\right) + \left(\operatorname{re}{\left(\begin{cases} \frac{a + 4}{2 \left(a - 2\right)} & \text{for}\: \frac{a + 4}{2 \left(a - 2\right)} \geq 0 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a + 4}{2 \left(a - 2\right)} & \text{for}\: \frac{a + 4}{2 \left(a - 2\right)} \geq 0 \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right)$$
//4 + a \ // 4 + a 4 + a \ // -4 + a \ //4 + a \ // 4 + a 4 + a \ // -4 + a \
||----- for And(a <= -4/5, a > -4)| ||---------- for ---------- >= 0| ||--------- for And(a > -2, a < -4/5)| ||----- for And(a <= -4/5, a > -4)| ||---------- for ---------- >= 0| ||--------- for And(a > -2, a < -4/5)|
I*im|< 2*a | + I*im|<2*(-2 + a) 2*(-2 + a) | + I*im|<2*(2 + a) | + re|< 2*a | + re|<2*(-2 + a) 2*(-2 + a) | + re|<2*(2 + a) |
|| | || | || | || | || | || |
\\ nan otherwise / \\ nan otherwise / \\ nan otherwise / \\ nan otherwise / \\ nan otherwise / \\ nan otherwise /
$$\operatorname{re}{\left(\begin{cases} \frac{a + 4}{2 a} & \text{for}\: a \leq - \frac{4}{5} \wedge a > -4 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + \operatorname{re}{\left(\begin{cases} \frac{a - 4}{2 \left(a + 2\right)} & \text{for}\: a > -2 \wedge a < - \frac{4}{5} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + \operatorname{re}{\left(\begin{cases} \frac{a + 4}{2 \left(a - 2\right)} & \text{for}\: \frac{a + 4}{2 \left(a - 2\right)} \geq 0 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a + 4}{2 a} & \text{for}\: a \leq - \frac{4}{5} \wedge a > -4 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a - 4}{2 \left(a + 2\right)} & \text{for}\: a > -2 \wedge a < - \frac{4}{5} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a + 4}{2 \left(a - 2\right)} & \text{for}\: \frac{a + 4}{2 \left(a - 2\right)} \geq 0 \\\text{NaN} & \text{otherwise} \end{cases}\right)}$$
/ //4 + a \ //4 + a \\ / // -4 + a \ // -4 + a \\ / // 4 + a 4 + a \ // 4 + a 4 + a \\
| ||----- for And(a <= -4/5, a > -4)| ||----- for And(a <= -4/5, a > -4)|| | ||--------- for And(a > -2, a < -4/5)| ||--------- for And(a > -2, a < -4/5)|| | ||---------- for ---------- >= 0| ||---------- for ---------- >= 0||
|I*im|< 2*a | + re|< 2*a ||*|I*im|<2*(2 + a) | + re|<2*(2 + a) ||*|I*im|<2*(-2 + a) 2*(-2 + a) | + re|<2*(-2 + a) 2*(-2 + a) ||
| || | || || | || | || || | || | || ||
\ \\ nan otherwise / \\ nan otherwise // \ \\ nan otherwise / \\ nan otherwise // \ \\ nan otherwise / \\ nan otherwise //
$$\left(\operatorname{re}{\left(\begin{cases} \frac{a + 4}{2 a} & \text{for}\: a \leq - \frac{4}{5} \wedge a > -4 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a + 4}{2 a} & \text{for}\: a \leq - \frac{4}{5} \wedge a > -4 \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right) \left(\operatorname{re}{\left(\begin{cases} \frac{a - 4}{2 \left(a + 2\right)} & \text{for}\: a > -2 \wedge a < - \frac{4}{5} \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a - 4}{2 \left(a + 2\right)} & \text{for}\: a > -2 \wedge a < - \frac{4}{5} \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right) \left(\operatorname{re}{\left(\begin{cases} \frac{a + 4}{2 \left(a - 2\right)} & \text{for}\: \frac{a + 4}{2 \left(a - 2\right)} \geq 0 \\\text{NaN} & \text{otherwise} \end{cases}\right)} + i \operatorname{im}{\left(\begin{cases} \frac{a + 4}{2 \left(a - 2\right)} & \text{for}\: \frac{a + 4}{2 \left(a - 2\right)} \geq 0 \\\text{NaN} & \text{otherwise} \end{cases}\right)}\right)$$
$$\text{NaN}$$