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sqrt(sin(x))*(4-5*cos(x)-2*(sin(x))^2)=0 la ecuación

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Solución numérica:

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Solución

Ha introducido [src]
  ________ /                    2   \    
\/ sin(x) *\4 - 5*cos(x) - 2*sin (x)/ = 0
$$\left(\left(4 - 5 \cos{\left(x \right)}\right) - 2 \sin^{2}{\left(x \right)}\right) \sqrt{\sin{\left(x \right)}} = 0$$
Solución detallada
Tenemos la ecuación
$$\left(\left(4 - 5 \cos{\left(x \right)}\right) - 2 \sin^{2}{\left(x \right)}\right) \sqrt{\sin{\left(x \right)}} = 0$$
cambiamos
$$\left(- 5 \cos{\left(x \right)} + \cos{\left(2 x \right)} + 3\right) \sqrt{\sin{\left(x \right)}} = 0$$
$$\left(2 \cos^{2}{\left(x \right)} - 5 \cos{\left(x \right)} + 2\right) \sqrt{\sin{\left(x \right)}} = 0$$
Sustituimos
$$w = \cos{\left(x \right)}$$
Abramos la expresión en la ecuación
$$\left(2 w^{2} - 5 w + 2\right) \sqrt{\sin{\left(x \right)}} = 0$$
Obtenemos la ecuación cuadrática
$$2 w^{2} \sqrt{\sin{\left(x \right)}} - 5 w \sqrt{\sin{\left(x \right)}} + 2 \sqrt{\sin{\left(x \right)}} = 0$$
Es la ecuación de la forma
a*w^2 + b*w + c = 0

La ecuación cuadrática puede ser resuelta
con la ayuda del discriminante.
Las raíces de la ecuación cuadrática:
$$w_{1} = \frac{\sqrt{D} - b}{2 a}$$
$$w_{2} = \frac{- \sqrt{D} - b}{2 a}$$
donde D = b^2 - 4*a*c es el discriminante.
Como
$$a = 2 \sqrt{\sin{\left(x \right)}}$$
$$b = - 5 \sqrt{\sin{\left(x \right)}}$$
$$c = 2 \sqrt{\sin{\left(x \right)}}$$
, entonces
D = b^2 - 4 * a * c = 

(-5*sqrt(sin(x)))^2 - 4 * (2*sqrt(sin(x))) * (2*sqrt(sin(x))) = 9*sin(x)

La ecuación tiene dos raíces.
w1 = (-b + sqrt(D)) / (2*a)

w2 = (-b - sqrt(D)) / (2*a)

o
$$w_{1} = 2$$
$$w_{2} = \frac{1}{2}$$
hacemos cambio inverso
$$\cos{\left(x \right)} = w$$
Tenemos la ecuación
$$\cos{\left(x \right)} = w$$
es la ecuación trigonométrica más simple
Esta ecuación se reorganiza en
$$x = \pi n + \operatorname{acos}{\left(w \right)}$$
$$x = \pi n + \operatorname{acos}{\left(w \right)} - \pi$$
O
$$x = \pi n + \operatorname{acos}{\left(w \right)}$$
$$x = \pi n + \operatorname{acos}{\left(w \right)} - \pi$$
, donde n es cualquier número entero
sustituimos w:
$$x_{1} = \pi n + \operatorname{acos}{\left(w_{1} \right)}$$
$$x_{1} = \pi n + \operatorname{acos}{\left(2 \right)}$$
$$x_{1} = \pi n + \operatorname{acos}{\left(2 \right)}$$
$$x_{2} = \pi n + \operatorname{acos}{\left(w_{2} \right)}$$
$$x_{2} = \pi n + \operatorname{acos}{\left(\frac{1}{2} \right)}$$
$$x_{2} = \pi n + \frac{\pi}{3}$$
$$x_{3} = \pi n + \operatorname{acos}{\left(w_{1} \right)} - \pi$$
$$x_{3} = \pi n - \pi + \operatorname{acos}{\left(2 \right)}$$
$$x_{3} = \pi n - \pi + \operatorname{acos}{\left(2 \right)}$$
$$x_{4} = \pi n + \operatorname{acos}{\left(w_{2} \right)} - \pi$$
$$x_{4} = \pi n - \pi + \operatorname{acos}{\left(\frac{1}{2} \right)}$$
$$x_{4} = \pi n - \frac{2 \pi}{3}$$
Gráfica
Suma y producto de raíces [src]
suma
                     /  ___\            /  ___\
  pi   pi            |\/ 3 |            |\/ 3 |
- -- + -- - 2*I*atanh|-----| + 2*I*atanh|-----|
  3    3             \  3  /            \  3  /
$$\left(\left(- \frac{\pi}{3} + \frac{\pi}{3}\right) - 2 i \operatorname{atanh}{\left(\frac{\sqrt{3}}{3} \right)}\right) + 2 i \operatorname{atanh}{\left(\frac{\sqrt{3}}{3} \right)}$$
=
0
$$0$$
producto
                    /  ___\          /  ___\
  -pi  pi           |\/ 3 |          |\/ 3 |
0*----*--*-2*I*atanh|-----|*2*I*atanh|-----|
   3   3            \  3  /          \  3  /
$$2 i \operatorname{atanh}{\left(\frac{\sqrt{3}}{3} \right)} - 2 i \operatorname{atanh}{\left(\frac{\sqrt{3}}{3} \right)} \frac{\pi}{3} \cdot 0 \left(- \frac{\pi}{3}\right)$$
=
0
$$0$$
0
Respuesta rápida [src]
x1 = 0
$$x_{1} = 0$$
     -pi 
x2 = ----
      3  
$$x_{2} = - \frac{\pi}{3}$$
     pi
x3 = --
     3 
$$x_{3} = \frac{\pi}{3}$$
               /  ___\
               |\/ 3 |
x4 = -2*I*atanh|-----|
               \  3  /
$$x_{4} = - 2 i \operatorname{atanh}{\left(\frac{\sqrt{3}}{3} \right)}$$
              /  ___\
              |\/ 3 |
x5 = 2*I*atanh|-----|
              \  3  /
$$x_{5} = 2 i \operatorname{atanh}{\left(\frac{\sqrt{3}}{3} \right)}$$
x5 = 2*i*atanh(sqrt(3)/3)
Respuesta numérica [src]
x1 = -13.6135681655558
x2 = 89.0117918517108
x3 = -55.5014702134197
x4 = -51.3126800086333
x5 = -95.2949771588904
x6 = -36.6519142918809
x7 = -30.3687289847013
x8 = -68.0678408277789
x9 = 51.3126800086333
x10 = 32.4631240870945
x11 = -82.7286065445312
x12 = -89.0117918517108
x13 = 63.8790506229925
x14 = -26.1799387799149
x15 = -42.9350995990605
x16 = 7.33038285837618
x17 = 95.2949771588904
x18 = -19.8967534727354
x19 = -7.33038285837618
x20 = -45.0294947014537
x21 = 36.6519142918809
x22 = -24.0855436775217
x23 = 13.6135681655558
x24 = 5.23598775598299
x25 = 0.0
x26 = -99.4837673636768
x27 = 45.0294947014537
x28 = 74.3510261349584
x29 = 42.9350995990605
x30 = 61.7846555205993
x31 = -70.162235930172
x32 = 24.0855436775217
x33 = 101.57816246607
x34 = 93.2005820564972
x35 = -86.9173967493176
x36 = -1.0471975511966
x37 = -11.5191730631626
x38 = -74.3510261349584
x39 = 49.2182849062401
x40 = 26.1799387799149
x41 = 80.634211442138
x42 = 30.3687289847013
x43 = -63.8790506229925
x44 = 86.9173967493176
x45 = 17.8023583703422
x46 = -17.8023583703422
x47 = -57.5958653158129
x48 = 1.0471975511966
x49 = 70.162235930172
x50 = -61.7846555205993
x51 = 68.0678408277789
x52 = 76.4454212373516
x53 = 19.8967534727354
x54 = -80.634211442138
x55 = 57.5958653158129
x56 = -38.7463093942741
x56 = -38.7463093942741