(4*x^3)+(2*x)+1=0 la ecuación
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Solución
Teorema de Cardano-Vieta
reescribamos la ecuación
(4x3+2x)+1=0de
ax3+bx2+cx+d=0como ecuación cúbica reducida
x3+abx2+acx+ad=0x3+2x+41=0px2+qx+v+x3=0donde
p=abp=0q=acq=21v=adv=41Fórmulas de Cardano-Vieta
x1+x2+x3=−px1x2+x1x3+x2x3=qx1x2x3=vx1+x2+x3=0x1x2+x1x3+x2x3=21x1x2x3=41
Gráfica
Suma y producto de raíces
[src]
________________ / ________________\ ________________ / ________________\ ________________
/ _____ | / _____ | / _____ | / _____ | / _____
/ 27 3*\/ 105 | ___ / 27 3*\/ 105 | / 27 3*\/ 105 | ___ / 27 3*\/ 105 | / 27 3*\/ 105
3 / -- + --------- | ___ \/ 3 *3 / -- + --------- | 3 / -- + --------- | ___ \/ 3 *3 / -- + --------- | 3 / -- + ---------
1 \/ 8 8 | \/ 3 \/ 8 8 | 1 \/ 8 8 | \/ 3 \/ 8 8 | 1 \/ 8 8
- ----------------------- + --------------------- + I*|----------------------- + ---------------------------| + - ----------------------- + --------------------- + I*|- ----------------------- - ---------------------------| + ----------------------- - ---------------------
________________ 6 | ________________ 6 | ________________ 6 | ________________ 6 | ________________ 3
/ _____ | / _____ | / _____ | / _____ | / _____
/ 27 3*\/ 105 | / 27 3*\/ 105 | / 27 3*\/ 105 | / 27 3*\/ 105 | / 27 3*\/ 105
4*3 / -- + --------- |4*3 / -- + --------- | 4*3 / -- + --------- | 4*3 / -- + --------- | 2*3 / -- + ---------
\/ 8 8 \ \/ 8 8 / \/ 8 8 \ \/ 8 8 / \/ 8 8
−33827+83105+23827+831051+−43827+831051+63827+83105+i−633827+83105−43827+831053+−43827+831051+63827+83105+i43827+831053+633827+83105
/ ________________\ / ________________\
| / _____ | | / _____ |
| ___ / 27 3*\/ 105 | | ___ / 27 3*\/ 105 |
| ___ \/ 3 *3 / -- + --------- | | ___ \/ 3 *3 / -- + --------- |
| \/ 3 \/ 8 8 | | \/ 3 \/ 8 8 |
I*|- ----------------------- - ---------------------------| + I*|----------------------- + ---------------------------|
| ________________ 6 | | ________________ 6 |
| / _____ | | / _____ |
| / 27 3*\/ 105 | | / 27 3*\/ 105 |
| 4*3 / -- + --------- | |4*3 / -- + --------- |
\ \/ 8 8 / \ \/ 8 8 /
i−633827+83105−43827+831053+i43827+831053+633827+83105
/ ________________ / ________________\\ / ________________ / ________________\\ / ________________\
| / _____ | / _____ || | / _____ | / _____ || | / _____ |
| / 27 3*\/ 105 | ___ / 27 3*\/ 105 || | / 27 3*\/ 105 | ___ / 27 3*\/ 105 || | / 27 3*\/ 105 |
| 3 / -- + --------- | ___ \/ 3 *3 / -- + --------- || | 3 / -- + --------- | ___ \/ 3 *3 / -- + --------- || | 3 / -- + --------- |
| 1 \/ 8 8 | \/ 3 \/ 8 8 || | 1 \/ 8 8 | \/ 3 \/ 8 8 || | 1 \/ 8 8 |
|- ----------------------- + --------------------- + I*|----------------------- + ---------------------------||*|- ----------------------- + --------------------- + I*|- ----------------------- - ---------------------------||*|----------------------- - ---------------------|
| ________________ 6 | ________________ 6 || | ________________ 6 | ________________ 6 || | ________________ 3 |
| / _____ | / _____ || | / _____ | / _____ || | / _____ |
| / 27 3*\/ 105 | / 27 3*\/ 105 || | / 27 3*\/ 105 | / 27 3*\/ 105 || | / 27 3*\/ 105 |
| 4*3 / -- + --------- |4*3 / -- + --------- || | 4*3 / -- + --------- | 4*3 / -- + --------- || |2*3 / -- + --------- |
\ \/ 8 8 \ \/ 8 8 // \ \/ 8 8 \ \/ 8 8 // \ \/ 8 8 /
−43827+831051+63827+83105+i43827+831053+633827+83105−43827+831051+63827+83105+i−633827+83105−43827+831053−33827+83105+23827+831051
________________ / ________________\
/ _____ | / _____ |
/ 27 3*\/ 105 | ___ / 27 3*\/ 105 |
3 / -- + --------- | ___ \/ 3 *3 / -- + --------- |
1 \/ 8 8 | \/ 3 \/ 8 8 |
x1 = - ----------------------- + --------------------- + I*|----------------------- + ---------------------------|
________________ 6 | ________________ 6 |
/ _____ | / _____ |
/ 27 3*\/ 105 | / 27 3*\/ 105 |
4*3 / -- + --------- |4*3 / -- + --------- |
\/ 8 8 \ \/ 8 8 /
x1=−43827+831051+63827+83105+i43827+831053+633827+83105
________________ / ________________\
/ _____ | / _____ |
/ 27 3*\/ 105 | ___ / 27 3*\/ 105 |
3 / -- + --------- | ___ \/ 3 *3 / -- + --------- |
1 \/ 8 8 | \/ 3 \/ 8 8 |
x2 = - ----------------------- + --------------------- + I*|- ----------------------- - ---------------------------|
________________ 6 | ________________ 6 |
/ _____ | / _____ |
/ 27 3*\/ 105 | / 27 3*\/ 105 |
4*3 / -- + --------- | 4*3 / -- + --------- |
\/ 8 8 \ \/ 8 8 /
x2=−43827+831051+63827+83105+i−633827+83105−43827+831053
________________
/ _____
/ 27 3*\/ 105
3 / -- + ---------
1 \/ 8 8
x3 = ----------------------- - ---------------------
________________ 3
/ _____
/ 27 3*\/ 105
2*3 / -- + ---------
\/ 8 8
x3=−33827+83105+23827+831051
x3 = -(27/8 + 3*sqrt(105)/8)^(1/3)/3 + 1/(2*(27/8 + 3*sqrt(105)/8)^(1/3))
x2 = 0.192729249264812 - 0.781942255263478*i
x3 = 0.192729249264812 + 0.781942255263478*i
x3 = 0.192729249264812 + 0.781942255263478*i