x^3+7*x^2-20*x-72=0 la ecuación
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Solución
Teorema de Cardano-Vieta
es ecuación cúbica reducida
px2+qx+v+x3=0donde
p=abp=7q=acq=−20v=adv=−72Fórmulas de Cardano-Vieta
x1+x2+x3=−px1x2+x1x3+x2x3=qx1x2x3=vx1+x2+x3=−7x1x2+x1x3+x2x3=−20x1x2x3=−72
/ 1 \ / / 1 \ \
109*re|--------------------------------------| | 109*im|--------------------------------------| |
| ___________________ / ___\| | | ___________________ / ___\| / / ______\\ / / ______\\| / / ______\\ / / ______\\
|3 / ______ | 1 I*\/ 3 || | |3 / ______ | 1 I*\/ 3 || _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|| _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|
|\/ 1 + 18*I*\/ 3997 *|- - - -------|| | |\/ 1 + 18*I*\/ 3997 *|- - - -------|| \/ 109 *sin|-----------------| \/ 327 *cos|-----------------|| \/ 327 *sin|-----------------| \/ 109 *cos|-----------------|
7 \ \ 2 2 // | \ \ 2 2 // \ 3 / \ 3 /| \ 3 / \ 3 /
x1 = - - - ---------------------------------------------- + I*|- ---------------------------------------------- + ------------------------------ + ------------------------------| - ------------------------------ + ------------------------------
3 3 \ 3 6 6 / 6 6
x1=−37−6327sin(3atan(183997))−3109re((−21−23i)31+183997i1)+6109cos(3atan(183997))+i−3109im((−21−23i)31+183997i1)+6109sin(3atan(183997))+6327cos(3atan(183997))
/ 1 \ / / 1 \ \
109*re|--------------------------------------| | 109*im|--------------------------------------| |
| ___________________ / ___\| | | ___________________ / ___\| / / ______\\ / / ______\\| / / ______\\ / / ______\\
|3 / ______ | 1 I*\/ 3 || | |3 / ______ | 1 I*\/ 3 || _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|| _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|
|\/ 1 + 18*I*\/ 3997 *|- - + -------|| | |\/ 1 + 18*I*\/ 3997 *|- - + -------|| \/ 327 *cos|-----------------| \/ 109 *sin|-----------------|| \/ 109 *cos|-----------------| \/ 327 *sin|-----------------|
7 \ \ 2 2 // | \ \ 2 2 // \ 3 / \ 3 /| \ 3 / \ 3 /
x2 = - - - ---------------------------------------------- + I*|- ---------------------------------------------- - ------------------------------ + ------------------------------| + ------------------------------ + ------------------------------
3 3 \ 3 6 6 / 6 6
x2=−37+6327sin(3atan(183997))+6109cos(3atan(183997))−3109re((−21+23i)31+183997i1)+i−6327cos(3atan(183997))+6109sin(3atan(183997))−3109im((−21+23i)31+183997i1)
___________________
3 / ______
7 109 \/ 1 + 18*I*\/ 3997
x3 = - - - ------------------------ - ----------------------
3 ___________________ 3
3 / ______
3*\/ 1 + 18*I*\/ 3997
x3=−37−331+183997i−331+183997i109
x3 = -7/3 - (1 + 18*sqrt(3997)*i)^(1/3)/3 - 109/(3*(1 + 18*sqrt(3997)*i)^(1/3))
Suma y producto de raíces
[src]
/ 1 \ / / 1 \ \ / 1 \ / / 1 \ \
109*re|--------------------------------------| | 109*im|--------------------------------------| | 109*re|--------------------------------------| | 109*im|--------------------------------------| |
| ___________________ / ___\| | | ___________________ / ___\| / / ______\\ / / ______\\| / / ______\\ / / ______\\ | ___________________ / ___\| | | ___________________ / ___\| / / ______\\ / / ______\\| / / ______\\ / / ______\\
|3 / ______ | 1 I*\/ 3 || | |3 / ______ | 1 I*\/ 3 || _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|| _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /| |3 / ______ | 1 I*\/ 3 || | |3 / ______ | 1 I*\/ 3 || _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|| _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /| ___________________
|\/ 1 + 18*I*\/ 3997 *|- - - -------|| | |\/ 1 + 18*I*\/ 3997 *|- - - -------|| \/ 109 *sin|-----------------| \/ 327 *cos|-----------------|| \/ 327 *sin|-----------------| \/ 109 *cos|-----------------| |\/ 1 + 18*I*\/ 3997 *|- - + -------|| | |\/ 1 + 18*I*\/ 3997 *|- - + -------|| \/ 327 *cos|-----------------| \/ 109 *sin|-----------------|| \/ 109 *cos|-----------------| \/ 327 *sin|-----------------| 3 / ______
7 \ \ 2 2 // | \ \ 2 2 // \ 3 / \ 3 /| \ 3 / \ 3 / 7 \ \ 2 2 // | \ \ 2 2 // \ 3 / \ 3 /| \ 3 / \ 3 / 7 109 \/ 1 + 18*I*\/ 3997
- - - ---------------------------------------------- + I*|- ---------------------------------------------- + ------------------------------ + ------------------------------| - ------------------------------ + ------------------------------ + - - - ---------------------------------------------- + I*|- ---------------------------------------------- - ------------------------------ + ------------------------------| + ------------------------------ + ------------------------------ + - - - ------------------------ - ----------------------
3 3 \ 3 6 6 / 6 6 3 3 \ 3 6 6 / 6 6 3 ___________________ 3
3 / ______
3*\/ 1 + 18*I*\/ 3997
(−37−331+183997i−331+183997i109)+−37−6327sin(3atan(183997))−3109re((−21−23i)31+183997i1)+6109cos(3atan(183997))+i−3109im((−21−23i)31+183997i1)+6109sin(3atan(183997))+6327cos(3atan(183997))+−37+6327sin(3atan(183997))+6109cos(3atan(183997))−3109re((−21+23i)31+183997i1)+i−6327cos(3atan(183997))+6109sin(3atan(183997))−3109im((−21+23i)31+183997i1)
/ 1 \ / 1 \ / / 1 \ \ / / 1 \ \
109*re|--------------------------------------| 109*re|--------------------------------------| | 109*im|--------------------------------------| | | 109*im|--------------------------------------| |
| ___________________ / ___\| | ___________________ / ___\| | | ___________________ / ___\| / / ______\\ / / ______\\| | | ___________________ / ___\| / / ______\\ / / ______\\| / / ______\\
|3 / ______ | 1 I*\/ 3 || |3 / ______ | 1 I*\/ 3 || ___________________ | |3 / ______ | 1 I*\/ 3 || _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|| | |3 / ______ | 1 I*\/ 3 || _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|| _____ |atan\18*\/ 3997 /|
|\/ 1 + 18*I*\/ 3997 *|- - + -------|| |\/ 1 + 18*I*\/ 3997 *|- - - -------|| 3 / ______ | |\/ 1 + 18*I*\/ 3997 *|- - + -------|| \/ 327 *cos|-----------------| \/ 109 *sin|-----------------|| | |\/ 1 + 18*I*\/ 3997 *|- - - -------|| \/ 109 *sin|-----------------| \/ 327 *cos|-----------------|| \/ 109 *cos|-----------------|
109 \ \ 2 2 // \ \ 2 2 // \/ 1 + 18*I*\/ 3997 | \ \ 2 2 // \ 3 / \ 3 /| | \ \ 2 2 // \ 3 / \ 3 /| \ 3 /
-7 - ------------------------ - ---------------------------------------------- - ---------------------------------------------- - ---------------------- + I*|- ---------------------------------------------- - ------------------------------ + ------------------------------| + I*|- ---------------------------------------------- + ------------------------------ + ------------------------------| + ------------------------------
___________________ 3 3 3 \ 3 6 6 / \ 3 6 6 / 3
3 / ______
3*\/ 1 + 18*I*\/ 3997
−7−3109re((−21−23i)31+183997i1)−3109re((−21+23i)31+183997i1)+3109cos(3atan(183997))−331+183997i+i−3109im((−21−23i)31+183997i1)+6109sin(3atan(183997))+6327cos(3atan(183997))+i−6327cos(3atan(183997))+6109sin(3atan(183997))−3109im((−21+23i)31+183997i1)−331+183997i109
/ / 1 \ / / 1 \ \ \ / / 1 \ / / 1 \ \ \
| 109*re|--------------------------------------| | 109*im|--------------------------------------| | | | 109*re|--------------------------------------| | 109*im|--------------------------------------| | |
| | ___________________ / ___\| | | ___________________ / ___\| / / ______\\ / / ______\\| / / ______\\ / / ______\\| | | ___________________ / ___\| | | ___________________ / ___\| / / ______\\ / / ______\\| / / ______\\ / / ______\\|
| |3 / ______ | 1 I*\/ 3 || | |3 / ______ | 1 I*\/ 3 || _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|| _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|| | |3 / ______ | 1 I*\/ 3 || | |3 / ______ | 1 I*\/ 3 || _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|| _____ |atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /|| / ___________________\
| |\/ 1 + 18*I*\/ 3997 *|- - - -------|| | |\/ 1 + 18*I*\/ 3997 *|- - - -------|| \/ 109 *sin|-----------------| \/ 327 *cos|-----------------|| \/ 327 *sin|-----------------| \/ 109 *cos|-----------------|| | |\/ 1 + 18*I*\/ 3997 *|- - + -------|| | |\/ 1 + 18*I*\/ 3997 *|- - + -------|| \/ 327 *cos|-----------------| \/ 109 *sin|-----------------|| \/ 109 *cos|-----------------| \/ 327 *sin|-----------------|| | 3 / ______ |
| 7 \ \ 2 2 // | \ \ 2 2 // \ 3 / \ 3 /| \ 3 / \ 3 /| | 7 \ \ 2 2 // | \ \ 2 2 // \ 3 / \ 3 /| \ 3 / \ 3 /| | 7 109 \/ 1 + 18*I*\/ 3997 |
|- - - ---------------------------------------------- + I*|- ---------------------------------------------- + ------------------------------ + ------------------------------| - ------------------------------ + ------------------------------|*|- - - ---------------------------------------------- + I*|- ---------------------------------------------- - ------------------------------ + ------------------------------| + ------------------------------ + ------------------------------|*|- - - ------------------------ - ----------------------|
\ 3 3 \ 3 6 6 / 6 6 / \ 3 3 \ 3 6 6 / 6 6 / | 3 ___________________ 3 |
| 3 / ______ |
\ 3*\/ 1 + 18*I*\/ 3997 /
−37−6327sin(3atan(183997))−3109re((−21−23i)31+183997i1)+6109cos(3atan(183997))+i−3109im((−21−23i)31+183997i1)+6109sin(3atan(183997))+6327cos(3atan(183997))−37+6327sin(3atan(183997))+6109cos(3atan(183997))−3109re((−21+23i)31+183997i1)+i−6327cos(3atan(183997))+6109sin(3atan(183997))−3109im((−21+23i)31+183997i1)(−37−331+183997i−331+183997i109)
/ ___________________ / ___________________\\ / / / ______\\ / / ______\\\
| 3 / ______ | 3 / ______ || | |2*atan\18*\/ 3997 /| _____ |atan\18*\/ 3997 /||
\109 + \/ 1 + 18*I*\/ 3997 *\7 + \/ 1 + 18*I*\/ 3997 //*|60 - 218*cos|-------------------| + 14*\/ 109 *cos|-----------------||
\ \ 3 / \ 3 //
-----------------------------------------------------------------------------------------------------------------------------------
___________________
3 / ______
27*\/ 1 + 18*I*\/ 3997
2731+183997i(109+31+183997i(7+31+183997i))(−218cos(32atan(183997))+60+14109cos(3atan(183997)))
(109 + (1 + 18*i*sqrt(3997))^(1/3)*(7 + (1 + 18*i*sqrt(3997))^(1/3)))*(60 - 218*cos(2*atan(18*sqrt(3997))/3) + 14*sqrt(109)*cos(atan(18*sqrt(3997))/3))/(27*(1 + 18*i*sqrt(3997))^(1/3))