Expresión del cuadrado perfecto
Expresemos el cuadrado perfecto del trinomio cuadrático
$$\left(y^{4} + y^{2}\right) + 7$$
Para eso usemos la fórmula
$$a y^{4} + b y^{2} + c = a \left(m + y^{2}\right)^{2} + n$$
donde
$$m = \frac{b}{2 a}$$
$$n = \frac{4 a c - b^{2}}{4 a}$$
En nuestro caso
$$a = 1$$
$$b = 1$$
$$c = 7$$
Entonces
$$m = \frac{1}{2}$$
$$n = \frac{27}{4}$$
Pues,
$$\left(y^{2} + \frac{1}{2}\right)^{2} + \frac{27}{4}$$
/ / / ___\\ / / ___\\\ / / / ___\\ / / ___\\\ / / / ___\\ / / ___\\\ / / / ___\\ / / ___\\\
| 4 ___ |atan\3*\/ 3 /| 4 ___ |atan\3*\/ 3 /|| | 4 ___ |atan\3*\/ 3 /| 4 ___ |atan\3*\/ 3 /|| | 4 ___ |atan\3*\/ 3 /| 4 ___ |atan\3*\/ 3 /|| | 4 ___ |atan\3*\/ 3 /| 4 ___ |atan\3*\/ 3 /||
|x + \/ 7 *sin|-------------| + I*\/ 7 *cos|-------------||*|x + \/ 7 *sin|-------------| - I*\/ 7 *cos|-------------||*|x + - \/ 7 *sin|-------------| + I*\/ 7 *cos|-------------||*|x + - \/ 7 *sin|-------------| - I*\/ 7 *cos|-------------||
\ \ 2 / \ 2 // \ \ 2 / \ 2 // \ \ 2 / \ 2 // \ \ 2 / \ 2 //
$$\left(x + \left(\sqrt[4]{7} \sin{\left(\frac{\operatorname{atan}{\left(3 \sqrt{3} \right)}}{2} \right)} - \sqrt[4]{7} i \cos{\left(\frac{\operatorname{atan}{\left(3 \sqrt{3} \right)}}{2} \right)}\right)\right) \left(x + \left(\sqrt[4]{7} \sin{\left(\frac{\operatorname{atan}{\left(3 \sqrt{3} \right)}}{2} \right)} + \sqrt[4]{7} i \cos{\left(\frac{\operatorname{atan}{\left(3 \sqrt{3} \right)}}{2} \right)}\right)\right) \left(x + \left(- \sqrt[4]{7} \sin{\left(\frac{\operatorname{atan}{\left(3 \sqrt{3} \right)}}{2} \right)} + \sqrt[4]{7} i \cos{\left(\frac{\operatorname{atan}{\left(3 \sqrt{3} \right)}}{2} \right)}\right)\right) \left(x + \left(- \sqrt[4]{7} \sin{\left(\frac{\operatorname{atan}{\left(3 \sqrt{3} \right)}}{2} \right)} - \sqrt[4]{7} i \cos{\left(\frac{\operatorname{atan}{\left(3 \sqrt{3} \right)}}{2} \right)}\right)\right)$$
(((x + 7^(1/4)*sin(atan(3*sqrt(3))/2) + i*7^(1/4)*cos(atan(3*sqrt(3))/2))*(x + 7^(1/4)*sin(atan(3*sqrt(3))/2) - i*7^(1/4)*cos(atan(3*sqrt(3))/2)))*(x - 7^(1/4)*sin(atan(3*sqrt(3))/2) + i*7^(1/4)*cos(atan(3*sqrt(3))/2)))*(x - 7^(1/4)*sin(atan(3*sqrt(3))/2) - i*7^(1/4)*cos(atan(3*sqrt(3))/2))