x.diff(x)=3*x-3*x^(4/3)*cos(y) equation
The teacher will be very surprised to see your correct solution 😉
The solution
Detail solution
Given the equation
$$1 = - 3 x^{\frac{4}{3}} \cos{\left(y \right)} + 3 x$$
- this is the simplest trigonometric equation
Divide both parts of the equation by 3*x^(4/3)
The equation is transformed to
$$\cos{\left(y \right)} = \frac{3 x - 1}{3 x^{\frac{4}{3}}}$$
This equation is transformed to
$$y = \pi n + \operatorname{acos}{\left(\frac{3 x - 1}{3 x^{\frac{4}{3}}} \right)}$$
$$y = \pi n + \operatorname{acos}{\left(\frac{3 x - 1}{3 x^{\frac{4}{3}}} \right)} - \pi$$
Or
$$y = \pi n + \operatorname{acos}{\left(\frac{3 x - 1}{3 x^{\frac{4}{3}}} \right)}$$
$$y = \pi n + \operatorname{acos}{\left(\frac{3 x - 1}{3 x^{\frac{4}{3}}} \right)} - \pi$$
, where n - is a integer
/-1 + 3*x\
y1 = - acos|--------| + 2*pi
| 4/3 |
\ 3*x /
$$y_{1} = - \operatorname{acos}{\left(\frac{3 x - 1}{3 x^{\frac{4}{3}}} \right)} + 2 \pi$$
/-1/3 + x\
y2 = acos|--------|
| 4/3 |
\ x /
$$y_{2} = \operatorname{acos}{\left(\frac{x - \frac{1}{3}}{x^{\frac{4}{3}}} \right)}$$
Sum and product of roots
[src]
/-1 + 3*x\ /-1/3 + x\
0 + - acos|--------| + 2*pi + acos|--------|
| 4/3 | | 4/3 |
\ 3*x / \ x /
$$\left(\left(- \operatorname{acos}{\left(\frac{3 x - 1}{3 x^{\frac{4}{3}}} \right)} + 2 \pi\right) + 0\right) + \operatorname{acos}{\left(\frac{x - \frac{1}{3}}{x^{\frac{4}{3}}} \right)}$$
/-1 + 3*x\ /-1/3 + x\
- acos|--------| + 2*pi + acos|--------|
| 4/3 | | 4/3 |
\ 3*x / \ x /
$$\operatorname{acos}{\left(\frac{x - \frac{1}{3}}{x^{\frac{4}{3}}} \right)} - \operatorname{acos}{\left(\frac{3 x - 1}{3 x^{\frac{4}{3}}} \right)} + 2 \pi$$
/ /-1 + 3*x\ \ /-1/3 + x\
1*|- acos|--------| + 2*pi|*acos|--------|
| | 4/3 | | | 4/3 |
\ \ 3*x / / \ x /
$$1 \left(- \operatorname{acos}{\left(\frac{3 x - 1}{3 x^{\frac{4}{3}}} \right)} + 2 \pi\right) \operatorname{acos}{\left(\frac{x - \frac{1}{3}}{x^{\frac{4}{3}}} \right)}$$
/ /-1 + 3*x\ \ /-1 + 3*x\
|- acos|--------| + 2*pi|*acos|--------|
| | 4/3 | | | 4/3 |
\ \ 3*x / / \ 3*x /
$$\left(- \operatorname{acos}{\left(\frac{3 x - 1}{3 x^{\frac{4}{3}}} \right)} + 2 \pi\right) \operatorname{acos}{\left(\frac{3 x - 1}{3 x^{\frac{4}{3}}} \right)}$$
(-acos((-1 + 3*x)/(3*x^(4/3))) + 2*pi)*acos((-1 + 3*x)/(3*x^(4/3)))