sin(pi*x)/3=-1/2 equation
The teacher will be very surprised to see your correct solution 😉
The solution
Detail solution
Given the equation
$$\frac{\sin{\left(\pi x \right)}}{3} = - \frac{1}{2}$$
- this is the simplest trigonometric equation
Divide both parts of the equation by 1/3
The equation is transformed to
$$\sin{\left(\pi x \right)} = - \frac{3}{2}$$
As right part of the equation
modulo =
True
but sin
can no be more than 1 or less than -1
so the solution of the equation d'not exist.
Sum and product of roots
[src]
pi + re(asin(3/2)) I*im(asin(3/2)) re(asin(3/2)) I*im(asin(3/2))
------------------ + --------------- + - ------------- - ---------------
pi pi pi pi
$$\left(\frac{\operatorname{re}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)} + \pi}{\pi} + \frac{i \operatorname{im}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}}{\pi}\right) + \left(- \frac{\operatorname{re}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}}{\pi} - \frac{i \operatorname{im}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}}{\pi}\right)$$
pi + re(asin(3/2)) re(asin(3/2))
------------------ - -------------
pi pi
$$- \frac{\operatorname{re}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}}{\pi} + \frac{\operatorname{re}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)} + \pi}{\pi}$$
/pi + re(asin(3/2)) I*im(asin(3/2))\ / re(asin(3/2)) I*im(asin(3/2))\
|------------------ + ---------------|*|- ------------- - ---------------|
\ pi pi / \ pi pi /
$$\left(\frac{\operatorname{re}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)} + \pi}{\pi} + \frac{i \operatorname{im}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}}{\pi}\right) \left(- \frac{\operatorname{re}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}}{\pi} - \frac{i \operatorname{im}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}}{\pi}\right)$$
-(I*im(asin(3/2)) + re(asin(3/2)))*(pi + I*im(asin(3/2)) + re(asin(3/2)))
--------------------------------------------------------------------------
2
pi
$$- \frac{\left(\operatorname{re}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)} + i \operatorname{im}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}\right) \left(\operatorname{re}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)} + \pi + i \operatorname{im}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}\right)}{\pi^{2}}$$
-(i*im(asin(3/2)) + re(asin(3/2)))*(pi + i*im(asin(3/2)) + re(asin(3/2)))/pi^2
pi + re(asin(3/2)) I*im(asin(3/2))
x1 = ------------------ + ---------------
pi pi
$$x_{1} = \frac{\operatorname{re}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)} + \pi}{\pi} + \frac{i \operatorname{im}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}}{\pi}$$
re(asin(3/2)) I*im(asin(3/2))
x2 = - ------------- - ---------------
pi pi
$$x_{2} = - \frac{\operatorname{re}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}}{\pi} - \frac{i \operatorname{im}{\left(\operatorname{asin}{\left(\frac{3}{2} \right)}\right)}}{\pi}$$
x2 = -re(asin(3/2))/pi - i*im(asin(3/2))/pi
x1 = 1.5 - 0.306348962530033*i
x2 = -0.5 + 0.306348962530033*i
x2 = -0.5 + 0.306348962530033*i