-x^3-x^2+161*x-80=0 la ecuación
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Solución
Teorema de Cardano-Vieta
reescribamos la ecuación
(161x+(−x3−x2))−80=0de
ax3+bx2+cx+d=0como ecuación cúbica reducida
x3+abx2+acx+ad=0x3+x2−161x+80=0px2+qx+v+x3=0donde
p=abp=1q=acq=−161v=adv=80Fórmulas de Cardano-Vieta
x1+x2+x3=−px1x2+x1x3+x2x3=qx1x2x3=vx1+x2+x3=−1x1x2+x1x3+x2x3=−161x1x2x3=80
/ 1 \ / / 1 \ \
484*re|----------------------------------------------| / / __________\\ | 484*im|----------------------------------------------| / / __________\\ / / __________\\| / / __________\\
| _________________________| | |3*\/ 48942255 || | | _________________________| | |3*\/ 48942255 || | |3*\/ 48942255 ||| | |3*\/ 48942255 ||
|/ ___\ / __________ | |atan|--------------|| | |/ ___\ / __________ | |atan|--------------|| |atan|--------------||| |atan|--------------||
|| 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| | || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| ___ | \ 3611 /|| ___ | \ 3611 /|
||- - - -------|*3 / ---- + ---------------- | 11*cos|--------------------| | ||- - - -------|*3 / ---- + ---------------- | 11*sin|--------------------| 11*\/ 3 *cos|--------------------|| 11*\/ 3 *sin|--------------------|
1 \\ 2 2 / \/ 2 2 / \ 3 / | \\ 2 2 / \/ 2 2 / \ 3 / \ 3 /| \ 3 /
x1 = - - - ------------------------------------------------------ + ---------------------------- + I*|- ------------------------------------------------------ + ---------------------------- + ----------------------------------| - ----------------------------------
3 3 3 \ 3 3 3 / 3
x1=−3113sin(3atan(3611348942255))−31−3484re((−21−23i)323611+2348942255i1)+311cos(3atan(3611348942255))+i−3484im((−21−23i)323611+2348942255i1)+311sin(3atan(3611348942255))+3113cos(3atan(3611348942255))
/ 1 \ / / 1 \ \
484*re|----------------------------------------------| / / __________\\ | 484*im|----------------------------------------------| / / __________\\ / / __________\\| / / __________\\
| _________________________| | |3*\/ 48942255 || | | _________________________| | |3*\/ 48942255 || | |3*\/ 48942255 ||| | |3*\/ 48942255 ||
|/ ___\ / __________ | |atan|--------------|| | |/ ___\ / __________ | |atan|--------------|| |atan|--------------||| |atan|--------------||
|| 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| | || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| ___ | \ 3611 /|| ___ | \ 3611 /|
||- - + -------|*3 / ---- + ---------------- | 11*cos|--------------------| | ||- - + -------|*3 / ---- + ---------------- | 11*sin|--------------------| 11*\/ 3 *cos|--------------------|| 11*\/ 3 *sin|--------------------|
1 \\ 2 2 / \/ 2 2 / \ 3 / | \\ 2 2 / \/ 2 2 / \ 3 / \ 3 /| \ 3 /
x2 = - - - ------------------------------------------------------ + ---------------------------- + I*|- ------------------------------------------------------ + ---------------------------- - ----------------------------------| + ----------------------------------
3 3 3 \ 3 3 3 / 3
x2=−31+3113sin(3atan(3611348942255))+311cos(3atan(3611348942255))−3484re((−21+23i)323611+2348942255i1)+i−3113cos(3atan(3611348942255))+311sin(3atan(3611348942255))−3484im((−21+23i)323611+2348942255i1)
_________________________
/ __________
/ 3611 3*I*\/ 48942255
3 / ---- + ----------------
1 484 \/ 2 2
x3 = - - - -------------------------------- - ------------------------------
3 _________________________ 3
/ __________
/ 3611 3*I*\/ 48942255
3*3 / ---- + ----------------
\/ 2 2
x3=−31−3323611+2348942255i−3323611+2348942255i484
x3 = -1/3 - (3611/2 + 3*sqrt(48942255)*i/2)^(1/3)/3 - 484/(3*(3611/2 + 3*sqrt(48942255)*i/2)^(1/3))
Suma y producto de raíces
[src]
/ 1 \ / / 1 \ \ / 1 \ / / 1 \ \
484*re|----------------------------------------------| / / __________\\ | 484*im|----------------------------------------------| / / __________\\ / / __________\\| / / __________\\ 484*re|----------------------------------------------| / / __________\\ | 484*im|----------------------------------------------| / / __________\\ / / __________\\| / / __________\\
| _________________________| | |3*\/ 48942255 || | | _________________________| | |3*\/ 48942255 || | |3*\/ 48942255 ||| | |3*\/ 48942255 || | _________________________| | |3*\/ 48942255 || | | _________________________| | |3*\/ 48942255 || | |3*\/ 48942255 ||| | |3*\/ 48942255 || _________________________
|/ ___\ / __________ | |atan|--------------|| | |/ ___\ / __________ | |atan|--------------|| |atan|--------------||| |atan|--------------|| |/ ___\ / __________ | |atan|--------------|| | |/ ___\ / __________ | |atan|--------------|| |atan|--------------||| |atan|--------------|| / __________
|| 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| | || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| ___ | \ 3611 /|| ___ | \ 3611 /| || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| | || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| ___ | \ 3611 /|| ___ | \ 3611 /| / 3611 3*I*\/ 48942255
||- - - -------|*3 / ---- + ---------------- | 11*cos|--------------------| | ||- - - -------|*3 / ---- + ---------------- | 11*sin|--------------------| 11*\/ 3 *cos|--------------------|| 11*\/ 3 *sin|--------------------| ||- - + -------|*3 / ---- + ---------------- | 11*cos|--------------------| | ||- - + -------|*3 / ---- + ---------------- | 11*sin|--------------------| 11*\/ 3 *cos|--------------------|| 11*\/ 3 *sin|--------------------| 3 / ---- + ----------------
1 \\ 2 2 / \/ 2 2 / \ 3 / | \\ 2 2 / \/ 2 2 / \ 3 / \ 3 /| \ 3 / 1 \\ 2 2 / \/ 2 2 / \ 3 / | \\ 2 2 / \/ 2 2 / \ 3 / \ 3 /| \ 3 / 1 484 \/ 2 2
- - - ------------------------------------------------------ + ---------------------------- + I*|- ------------------------------------------------------ + ---------------------------- + ----------------------------------| - ---------------------------------- + - - - ------------------------------------------------------ + ---------------------------- + I*|- ------------------------------------------------------ + ---------------------------- - ----------------------------------| + ---------------------------------- + - - - -------------------------------- - ------------------------------
3 3 3 \ 3 3 3 / 3 3 3 3 \ 3 3 3 / 3 3 _________________________ 3
/ __________
/ 3611 3*I*\/ 48942255
3*3 / ---- + ----------------
\/ 2 2
−3113sin(3atan(3611348942255))−31−3484re((−21−23i)323611+2348942255i1)+311cos(3atan(3611348942255))+i−3484im((−21−23i)323611+2348942255i1)+311sin(3atan(3611348942255))+3113cos(3atan(3611348942255))+−31+3113sin(3atan(3611348942255))+311cos(3atan(3611348942255))−3484re((−21+23i)323611+2348942255i1)+i−3113cos(3atan(3611348942255))+311sin(3atan(3611348942255))−3484im((−21+23i)323611+2348942255i1)+−31−3323611+2348942255i−3323611+2348942255i484
/ 1 \ / 1 \ / / 1 \ \ / / 1 \ \
484*re|----------------------------------------------| 484*re|----------------------------------------------| / / __________\\ | 484*im|----------------------------------------------| / / __________\\ / / __________\\| | 484*im|----------------------------------------------| / / __________\\ / / __________\\|
| _________________________| | _________________________| _________________________ | |3*\/ 48942255 || | | _________________________| | |3*\/ 48942255 || | |3*\/ 48942255 ||| | | _________________________| | |3*\/ 48942255 || | |3*\/ 48942255 |||
|/ ___\ / __________ | |/ ___\ / __________ | / __________ |atan|--------------|| | |/ ___\ / __________ | |atan|--------------|| |atan|--------------||| | |/ ___\ / __________ | |atan|--------------|| |atan|--------------|||
|| 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | / 3611 3*I*\/ 48942255 | \ 3611 /| | || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| ___ | \ 3611 /|| | || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| ___ | \ 3611 /||
||- - + -------|*3 / ---- + ---------------- | ||- - - -------|*3 / ---- + ---------------- | 3 / ---- + ---------------- 22*cos|--------------------| | ||- - + -------|*3 / ---- + ---------------- | 11*sin|--------------------| 11*\/ 3 *cos|--------------------|| | ||- - - -------|*3 / ---- + ---------------- | 11*sin|--------------------| 11*\/ 3 *cos|--------------------||
484 \\ 2 2 / \/ 2 2 / \\ 2 2 / \/ 2 2 / \/ 2 2 \ 3 / | \\ 2 2 / \/ 2 2 / \ 3 / \ 3 /| | \\ 2 2 / \/ 2 2 / \ 3 / \ 3 /|
-1 - -------------------------------- - ------------------------------------------------------ - ------------------------------------------------------ - ------------------------------ + ---------------------------- + I*|- ------------------------------------------------------ + ---------------------------- - ----------------------------------| + I*|- ------------------------------------------------------ + ---------------------------- + ----------------------------------|
_________________________ 3 3 3 3 \ 3 3 3 / \ 3 3 3 /
/ __________
/ 3611 3*I*\/ 48942255
3*3 / ---- + ----------------
\/ 2 2
−1−3484re((−21−23i)323611+2348942255i1)−3484re((−21+23i)323611+2348942255i1)+322cos(3atan(3611348942255))−3323611+2348942255i+i−3113cos(3atan(3611348942255))+311sin(3atan(3611348942255))−3484im((−21+23i)323611+2348942255i1)+i−3484im((−21−23i)323611+2348942255i1)+311sin(3atan(3611348942255))+3113cos(3atan(3611348942255))−3323611+2348942255i484
/ / 1 \ / / 1 \ \ \ / / 1 \ / / 1 \ \ \
| 484*re|----------------------------------------------| / / __________\\ | 484*im|----------------------------------------------| / / __________\\ / / __________\\| / / __________\\| | 484*re|----------------------------------------------| / / __________\\ | 484*im|----------------------------------------------| / / __________\\ / / __________\\| / / __________\\|
| | _________________________| | |3*\/ 48942255 || | | _________________________| | |3*\/ 48942255 || | |3*\/ 48942255 ||| | |3*\/ 48942255 ||| | | _________________________| | |3*\/ 48942255 || | | _________________________| | |3*\/ 48942255 || | |3*\/ 48942255 ||| | |3*\/ 48942255 ||| / _________________________\
| |/ ___\ / __________ | |atan|--------------|| | |/ ___\ / __________ | |atan|--------------|| |atan|--------------||| |atan|--------------||| | |/ ___\ / __________ | |atan|--------------|| | |/ ___\ / __________ | |atan|--------------|| |atan|--------------||| |atan|--------------||| | / __________ |
| || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| | || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| ___ | \ 3611 /|| ___ | \ 3611 /|| | || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| | || 1 I*\/ 3 | / 3611 3*I*\/ 48942255 | | \ 3611 /| ___ | \ 3611 /|| ___ | \ 3611 /|| | / 3611 3*I*\/ 48942255 |
| ||- - - -------|*3 / ---- + ---------------- | 11*cos|--------------------| | ||- - - -------|*3 / ---- + ---------------- | 11*sin|--------------------| 11*\/ 3 *cos|--------------------|| 11*\/ 3 *sin|--------------------|| | ||- - + -------|*3 / ---- + ---------------- | 11*cos|--------------------| | ||- - + -------|*3 / ---- + ---------------- | 11*sin|--------------------| 11*\/ 3 *cos|--------------------|| 11*\/ 3 *sin|--------------------|| | 3 / ---- + ---------------- |
| 1 \\ 2 2 / \/ 2 2 / \ 3 / | \\ 2 2 / \/ 2 2 / \ 3 / \ 3 /| \ 3 /| | 1 \\ 2 2 / \/ 2 2 / \ 3 / | \\ 2 2 / \/ 2 2 / \ 3 / \ 3 /| \ 3 /| | 1 484 \/ 2 2 |
|- - - ------------------------------------------------------ + ---------------------------- + I*|- ------------------------------------------------------ + ---------------------------- + ----------------------------------| - ----------------------------------|*|- - - ------------------------------------------------------ + ---------------------------- + I*|- ------------------------------------------------------ + ---------------------------- - ----------------------------------| + ----------------------------------|*|- - - -------------------------------- - ------------------------------|
\ 3 3 3 \ 3 3 3 / 3 / \ 3 3 3 \ 3 3 3 / 3 / | 3 _________________________ 3 |
| / __________ |
| / 3611 3*I*\/ 48942255 |
| 3*3 / ---- + ---------------- |
\ \/ 2 2 /
−31+3113sin(3atan(3611348942255))+311cos(3atan(3611348942255))−3484re((−21+23i)323611+2348942255i1)+i−3113cos(3atan(3611348942255))+311sin(3atan(3611348942255))−3484im((−21+23i)323611+2348942255i1)−3113sin(3atan(3611348942255))−31−3484re((−21−23i)323611+2348942255i1)+311cos(3atan(3611348942255))+i−3484im((−21−23i)323611+2348942255i1)+311sin(3atan(3611348942255))+3113cos(3atan(3611348942255))−31−3323611+2348942255i−3323611+2348942255i484
/ / / __________\\ / / __________\\\
| | |3*\/ 48942255 || | |3*\/ 48942255 |||
/ _________________________ / _________________________\\ | |2*atan|--------------|| |atan|--------------|||
| 3 ___ 3 / __________ | 2/3 3 / __________ || | | \ 3611 /| | \ 3611 /||
\968*\/ 2 + \/ 3611 + 3*I*\/ 48942255 *\2 + 2 *\/ 3611 + 3*I*\/ 48942255 //*|483 - 968*cos|----------------------| + 44*cos|--------------------||
\ \ 3 / \ 3 //
---------------------------------------------------------------------------------------------------------------------------------------------------------
_________________________
3 / __________
54*\/ 3611 + 3*I*\/ 48942255
5433611+348942255i(96832+(2+23233611+348942255i)33611+348942255i)(−968cos(32atan(3611348942255))+44cos(3atan(3611348942255))+483)
(968*2^(1/3) + (3611 + 3*i*sqrt(48942255))^(1/3)*(2 + 2^(2/3)*(3611 + 3*i*sqrt(48942255))^(1/3)))*(483 - 968*cos(2*atan(3*sqrt(48942255)/3611)/3) + 44*cos(atan(3*sqrt(48942255)/3611)/3))/(54*(3611 + 3*i*sqrt(48942255))^(1/3))