x^6=(6x-8)^3 equation
The teacher will be very surprised to see your correct solution 😉
The solution
$$x_{1} = 2$$
$$x_{2} = 4$$
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3 | 3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /|
x_3 = - - + I*|- ------- + \/ 217 *cos|--------------|| + \/ 217 *sin|--------------|
2 \ 2 \ 2 // \ 2 /
$$x_{3} = - \frac{3}{2} + \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} + i \left(- \frac{3 \sqrt{3}}{2} + \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)}\right)$$
/ ___ / / ___\\\ / / ___\\
3 |3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /|
x_4 = - - + I*|------- + \/ 217 *cos|--------------|| - \/ 217 *sin|--------------|
2 \ 2 \ 2 // \ 2 /
$$x_{4} = - \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} - \frac{3}{2} + i \left(\frac{3 \sqrt{3}}{2} + \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)}\right)$$
/ ___ / / ___\\\ / / ___\\
3 |3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /|
x_5 = - - + I*|------- - \/ 217 *cos|--------------|| + \/ 217 *sin|--------------|
2 \ 2 \ 2 // \ 2 /
$$x_{5} = - \frac{3}{2} + \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} + i \left(- \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} + \frac{3 \sqrt{3}}{2}\right)$$
/ ___ / / ___\\\ / / ___\\
3 | 3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /|
x_6 = - - + I*|- ------- - \/ 217 *cos|--------------|| - \/ 217 *sin|--------------|
2 \ 2 \ 2 // \ 2 /
$$x_{6} = - \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} - \frac{3}{2} + i \left(- \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} - \frac{3 \sqrt{3}}{2}\right)$$
Sum and product of roots
[src]
/ ___ / / ___\\\ / / ___\\ / ___ / / ___\\\ / / ___\\ / ___ / / ___\\\ / / ___\\ / ___ / / ___\\\ / / ___\\
3 | 3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /| 3 |3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /| 3 |3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /| 3 | 3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /|
2 + 4 + - - + I*|- ------- + \/ 217 *cos|--------------|| + \/ 217 *sin|--------------| + - - + I*|------- + \/ 217 *cos|--------------|| - \/ 217 *sin|--------------| + - - + I*|------- - \/ 217 *cos|--------------|| + \/ 217 *sin|--------------| + - - + I*|- ------- - \/ 217 *cos|--------------|| - \/ 217 *sin|--------------|
2 \ 2 \ 2 // \ 2 / 2 \ 2 \ 2 // \ 2 / 2 \ 2 \ 2 // \ 2 / 2 \ 2 \ 2 // \ 2 /
$$\left(2\right) + \left(4\right) + \left(- \frac{3}{2} + \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} + i \left(- \frac{3 \sqrt{3}}{2} + \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)}\right)\right) + \left(- \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} - \frac{3}{2} + i \left(\frac{3 \sqrt{3}}{2} + \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)}\right)\right) + \left(- \frac{3}{2} + \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} + i \left(- \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} + \frac{3 \sqrt{3}}{2}\right)\right) + \left(- \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} - \frac{3}{2} + i \left(- \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} - \frac{3 \sqrt{3}}{2}\right)\right)$$
/ ___ / / ___\\\ / ___ / / ___\\\ / ___ / / ___\\\ / ___ / / ___\\\
| 3*\/ 3 4 _____ |atan\17*\/ 3 /|| | 3*\/ 3 4 _____ |atan\17*\/ 3 /|| |3*\/ 3 4 _____ |atan\17*\/ 3 /|| |3*\/ 3 4 _____ |atan\17*\/ 3 /||
I*|- ------- + \/ 217 *cos|--------------|| + I*|- ------- - \/ 217 *cos|--------------|| + I*|------- + \/ 217 *cos|--------------|| + I*|------- - \/ 217 *cos|--------------||
\ 2 \ 2 // \ 2 \ 2 // \ 2 \ 2 // \ 2 \ 2 //
$$i \left(- \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} - \frac{3 \sqrt{3}}{2}\right) + i \left(- \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} + \frac{3 \sqrt{3}}{2}\right) + i \left(- \frac{3 \sqrt{3}}{2} + \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)}\right) + i \left(\frac{3 \sqrt{3}}{2} + \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)}\right)$$
/ ___ / / ___\\\ / / ___\\ / ___ / / ___\\\ / / ___\\ / ___ / / ___\\\ / / ___\\ / ___ / / ___\\\ / / ___\\
3 | 3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /| 3 |3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /| 3 |3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /| 3 | 3*\/ 3 4 _____ |atan\17*\/ 3 /|| 4 _____ |atan\17*\/ 3 /|
2 * 4 * - - + I*|- ------- + \/ 217 *cos|--------------|| + \/ 217 *sin|--------------| * - - + I*|------- + \/ 217 *cos|--------------|| - \/ 217 *sin|--------------| * - - + I*|------- - \/ 217 *cos|--------------|| + \/ 217 *sin|--------------| * - - + I*|- ------- - \/ 217 *cos|--------------|| - \/ 217 *sin|--------------|
2 \ 2 \ 2 // \ 2 / 2 \ 2 \ 2 // \ 2 / 2 \ 2 \ 2 // \ 2 / 2 \ 2 \ 2 // \ 2 /
$$\left(2\right) * \left(4\right) * \left(- \frac{3}{2} + \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} + i \left(- \frac{3 \sqrt{3}}{2} + \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)}\right)\right) * \left(- \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} - \frac{3}{2} + i \left(\frac{3 \sqrt{3}}{2} + \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)}\right)\right) * \left(- \frac{3}{2} + \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} + i \left(- \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} + \frac{3 \sqrt{3}}{2}\right)\right) * \left(- \sqrt[4]{217} \sin{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} - \frac{3}{2} + i \left(- \sqrt[4]{217} \cos{\left(\frac{\operatorname{atan}{\left(17 \sqrt{3} \right)}}{2} \right)} - \frac{3 \sqrt{3}}{2}\right)\right)$$
$$512$$
x1 = 1.16748194582983 + 0.161536067813473*i
x2 = 1.16748194582983 - 0.161536067813473*i
x3 = -4.16748194582983 + 5.3576884905201*i
x4 = -4.16748194582983 - 5.3576884905201*i