Teorema de Cardano-Vieta
reescribamos la ecuación
$$\left(- 4 y + \left(x + 2 y^{2}\right)\right) + 4 = \left(0 x - 2 y\right) + 4$$
de
$$a y^{2} + b y + c = 0$$
como ecuación cuadrática reducida
$$y^{2} + \frac{b y}{a} + \frac{c}{a} = 0$$
$$\frac{x}{2} + y^{2} - y = 0$$
$$p y + q + y^{2} = 0$$
donde
$$p = \frac{b}{a}$$
$$p = -1$$
$$q = \frac{c}{a}$$
$$q = \frac{x}{2}$$
Fórmulas de Cardano-Vieta
$$y_{1} + y_{2} = - p$$
$$y_{1} y_{2} = q$$
$$y_{1} + y_{2} = 1$$
$$y_{1} y_{2} = \frac{x}{2}$$
___________________________ ___________________________
4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\ 4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\
\/ (1 - 2*re(x)) + 4*im (x) *cos|----------------------------| I*\/ (1 - 2*re(x)) + 4*im (x) *sin|----------------------------|
1 \ 2 / \ 2 /
y1 = - - ---------------------------------------------------------------- - ------------------------------------------------------------------
2 2 2
$$y_{1} = - \frac{i \sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} - \frac{\sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} + \frac{1}{2}$$
___________________________ ___________________________
4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\ 4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\
\/ (1 - 2*re(x)) + 4*im (x) *cos|----------------------------| I*\/ (1 - 2*re(x)) + 4*im (x) *sin|----------------------------|
1 \ 2 / \ 2 /
y2 = - + ---------------------------------------------------------------- + ------------------------------------------------------------------
2 2 2
$$y_{2} = \frac{i \sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} + \frac{\sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} + \frac{1}{2}$$
y2 = i*((1 - 2*re(x))^2 + 4*im(x)^2)^(1/4)*sin(atan2(-2*im(x, 1 - 2*re(x))/2)/2 + ((1 - 2*re(x))^2 + 4*im(x)^2)^(1/4)*cos(atan2(-2*im(x), 1 - 2*re(x))/2)/2 + 1/2)
Suma y producto de raíces
[src]
___________________________ ___________________________ ___________________________ ___________________________
4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\ 4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\ 4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\ 4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\
\/ (1 - 2*re(x)) + 4*im (x) *cos|----------------------------| I*\/ (1 - 2*re(x)) + 4*im (x) *sin|----------------------------| \/ (1 - 2*re(x)) + 4*im (x) *cos|----------------------------| I*\/ (1 - 2*re(x)) + 4*im (x) *sin|----------------------------|
1 \ 2 / \ 2 / 1 \ 2 / \ 2 /
- - ---------------------------------------------------------------- - ------------------------------------------------------------------ + - + ---------------------------------------------------------------- + ------------------------------------------------------------------
2 2 2 2 2 2
$$\left(- \frac{i \sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} - \frac{\sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} + \frac{1}{2}\right) + \left(\frac{i \sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} + \frac{\sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} + \frac{1}{2}\right)$$
$$1$$
/ ___________________________ ___________________________ \ / ___________________________ ___________________________ \
| 4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\ 4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\| | 4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\ 4 / 2 2 /atan2(-2*im(x), 1 - 2*re(x))\|
| \/ (1 - 2*re(x)) + 4*im (x) *cos|----------------------------| I*\/ (1 - 2*re(x)) + 4*im (x) *sin|----------------------------|| | \/ (1 - 2*re(x)) + 4*im (x) *cos|----------------------------| I*\/ (1 - 2*re(x)) + 4*im (x) *sin|----------------------------||
|1 \ 2 / \ 2 /| |1 \ 2 / \ 2 /|
|- - ---------------------------------------------------------------- - ------------------------------------------------------------------|*|- + ---------------------------------------------------------------- + ------------------------------------------------------------------|
\2 2 2 / \2 2 2 /
$$\left(- \frac{i \sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} - \frac{\sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} + \frac{1}{2}\right) \left(\frac{i \sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \sin{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} + \frac{\sqrt[4]{\left(1 - 2 \operatorname{re}{\left(x\right)}\right)^{2} + 4 \left(\operatorname{im}{\left(x\right)}\right)^{2}} \cos{\left(\frac{\operatorname{atan_{2}}{\left(- 2 \operatorname{im}{\left(x\right)},1 - 2 \operatorname{re}{\left(x\right)} \right)}}{2} \right)}}{2} + \frac{1}{2}\right)$$
re(x) I*im(x)
----- + -------
2 2
$$\frac{\operatorname{re}{\left(x\right)}}{2} + \frac{i \operatorname{im}{\left(x\right)}}{2}$$