x^3-5x^2-9x-45=0 la ecuación
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Solución
Teorema de Cardano-Vieta
es ecuación cúbica reducida
px2+qx+v+x3=0donde
p=abp=−5q=acq=−9v=adv=−45Fórmulas de Cardano-Vieta
x1+x2+x3=−px1x2+x1x3+x2x3=qx1x2x3=vx1+x2+x3=5x1x2+x1x3+x2x3=−9x1x2x3=−45
________________ / ________________ \
/ ______ | / ______ |
/ 935 \/ 9057 | ___ / 935 \/ 9057 |
3 / --- + -------- | \/ 3 *3 / --- + -------- ___ |
5 26 \/ 27 3 | \/ 27 3 26*\/ 3 |
x1 = - - ----------------------- - --------------------- + I*|- --------------------------- + -----------------------|
3 ________________ 2 | 2 ________________|
/ ______ | / ______ |
/ 935 \/ 9057 | / 935 \/ 9057 |
9*3 / --- + -------- | 9*3 / --- + -------- |
\/ 27 3 \ \/ 27 3 /
x1=−2339057+27935−9339057+2793526+35+i−23339057+27935+9339057+27935263
________________ / ________________ \
/ ______ | / ______ |
/ 935 \/ 9057 | ___ / 935 \/ 9057 |
3 / --- + -------- |\/ 3 *3 / --- + -------- ___ |
5 26 \/ 27 3 | \/ 27 3 26*\/ 3 |
x2 = - - ----------------------- - --------------------- + I*|--------------------------- - -----------------------|
3 ________________ 2 | 2 ________________|
/ ______ | / ______ |
/ 935 \/ 9057 | / 935 \/ 9057 |
9*3 / --- + -------- | 9*3 / --- + -------- |
\/ 27 3 \ \/ 27 3 /
x2=−2339057+27935−9339057+2793526+35+i−9339057+27935263+23339057+27935
________________
/ ______
5 / 935 \/ 9057 52
x3 = - + 3 / --- + -------- + -----------------------
3 \/ 27 3 ________________
/ ______
/ 935 \/ 9057
9*3 / --- + --------
\/ 27 3
x3=9339057+2793552+35+339057+27935
x3 = 52/(9*(sqrt(9057)/3 + 935/27)^(1/3)) + 5/3 + (sqrt(9057)/3 + 935/27)^(1/3)
Suma y producto de raíces
[src]
________________ / ________________ \ ________________ / ________________ \
/ ______ | / ______ | / ______ | / ______ |
/ 935 \/ 9057 | ___ / 935 \/ 9057 | / 935 \/ 9057 | ___ / 935 \/ 9057 | ________________
3 / --- + -------- | \/ 3 *3 / --- + -------- ___ | 3 / --- + -------- |\/ 3 *3 / --- + -------- ___ | / ______
5 26 \/ 27 3 | \/ 27 3 26*\/ 3 | 5 26 \/ 27 3 | \/ 27 3 26*\/ 3 | 5 / 935 \/ 9057 52
- - ----------------------- - --------------------- + I*|- --------------------------- + -----------------------| + - - ----------------------- - --------------------- + I*|--------------------------- - -----------------------| + - + 3 / --- + -------- + -----------------------
3 ________________ 2 | 2 ________________| 3 ________________ 2 | 2 ________________| 3 \/ 27 3 ________________
/ ______ | / ______ | / ______ | / ______ | / ______
/ 935 \/ 9057 | / 935 \/ 9057 | / 935 \/ 9057 | / 935 \/ 9057 | / 935 \/ 9057
9*3 / --- + -------- | 9*3 / --- + -------- | 9*3 / --- + -------- | 9*3 / --- + -------- | 9*3 / --- + --------
\/ 27 3 \ \/ 27 3 / \/ 27 3 \ \/ 27 3 / \/ 27 3
9339057+2793552+35+339057+27935+−2339057+27935−9339057+2793526+35+i−23339057+27935+9339057+27935263+−2339057+27935−9339057+2793526+35+i−9339057+27935263+23339057+27935
/ ________________ \ / ________________ \
| / ______ | | / ______ |
| ___ / 935 \/ 9057 | | ___ / 935 \/ 9057 |
|\/ 3 *3 / --- + -------- ___ | | \/ 3 *3 / --- + -------- ___ |
| \/ 27 3 26*\/ 3 | | \/ 27 3 26*\/ 3 |
5 + I*|--------------------------- - -----------------------| + I*|- --------------------------- + -----------------------|
| 2 ________________| | 2 ________________|
| / ______ | | / ______ |
| / 935 \/ 9057 | | / 935 \/ 9057 |
| 9*3 / --- + -------- | | 9*3 / --- + -------- |
\ \/ 27 3 / \ \/ 27 3 /
5+i−23339057+27935+9339057+27935263+i−9339057+27935263+23339057+27935
/ ________________ / ________________ \\ / ________________ / ________________ \\
| / ______ | / ______ || | / ______ | / ______ ||
| / 935 \/ 9057 | ___ / 935 \/ 9057 || | / 935 \/ 9057 | ___ / 935 \/ 9057 || / ________________ \
| 3 / --- + -------- | \/ 3 *3 / --- + -------- ___ || | 3 / --- + -------- |\/ 3 *3 / --- + -------- ___ || | / ______ |
|5 26 \/ 27 3 | \/ 27 3 26*\/ 3 || |5 26 \/ 27 3 | \/ 27 3 26*\/ 3 || |5 / 935 \/ 9057 52 |
|- - ----------------------- - --------------------- + I*|- --------------------------- + -----------------------||*|- - ----------------------- - --------------------- + I*|--------------------------- - -----------------------||*|- + 3 / --- + -------- + -----------------------|
|3 ________________ 2 | 2 ________________|| |3 ________________ 2 | 2 ________________|| |3 \/ 27 3 ________________|
| / ______ | / ______ || | / ______ | / ______ || | / ______ |
| / 935 \/ 9057 | / 935 \/ 9057 || | / 935 \/ 9057 | / 935 \/ 9057 || | / 935 \/ 9057 |
| 9*3 / --- + -------- | 9*3 / --- + -------- || | 9*3 / --- + -------- | 9*3 / --- + -------- || | 9*3 / --- + -------- |
\ \/ 27 3 \ \/ 27 3 // \ \/ 27 3 \ \/ 27 3 // \ \/ 27 3 /
−2339057+27935−9339057+2793526+35+i−9339057+27935263+23339057+27935−2339057+27935−9339057+2793526+35+i−23339057+27935+9339057+279352639339057+2793552+35+339057+27935
x1 = -1.07112748277456 + 2.27006984051383*i
x3 = -1.07112748277456 - 2.27006984051383*i
x3 = -1.07112748277456 - 2.27006984051383*i