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8*cos(x)^(2)+6*sin(x)-3=0

8*cos(x)^(2)+6*sin(x)-3=0 la ecuación

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Solución numérica:

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Solución

Ha introducido [src]
     2                      
8*cos (x) + 6*sin(x) - 3 = 0
$$\left(6 \sin{\left(x \right)} + 8 \cos^{2}{\left(x \right)}\right) - 3 = 0$$
Solución detallada
Tenemos la ecuación
$$\left(6 \sin{\left(x \right)} + 8 \cos^{2}{\left(x \right)}\right) - 3 = 0$$
cambiamos
$$- 8 \sin^{2}{\left(x \right)} + 6 \sin{\left(x \right)} + 5 = 0$$
$$- 8 \sin^{2}{\left(x \right)} + 6 \sin{\left(x \right)} + 5 = 0$$
Sustituimos
$$w = \sin{\left(x \right)}$$
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
$$a = -8$$
$$b = 6$$
$$c = 5$$
, entonces
D = b^2 - 4 * a * c = 

(6)^2 - 4 * (-8) * (5) = 196

Como D > 0 la ecuación tiene dos raíces.
w1 = (-b + sqrt(D)) / (2*a)

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

o
$$w_{1} = - \frac{1}{2}$$
$$w_{2} = \frac{5}{4}$$
hacemos cambio inverso
$$\sin{\left(x \right)} = w$$
Tenemos la ecuación
$$\sin{\left(x \right)} = w$$
es la ecuación trigonométrica más simple
Esta ecuación se reorganiza en
$$x = 2 \pi n + \operatorname{asin}{\left(w \right)}$$
$$x = 2 \pi n - \operatorname{asin}{\left(w \right)} + \pi$$
O
$$x = 2 \pi n + \operatorname{asin}{\left(w \right)}$$
$$x = 2 \pi n - \operatorname{asin}{\left(w \right)} + \pi$$
, donde n es cualquier número entero
sustituimos w:
$$x_{1} = 2 \pi n + \operatorname{asin}{\left(w_{1} \right)}$$
$$x_{1} = 2 \pi n + \operatorname{asin}{\left(- \frac{1}{2} \right)}$$
$$x_{1} = 2 \pi n - \frac{\pi}{6}$$
$$x_{2} = 2 \pi n + \operatorname{asin}{\left(w_{2} \right)}$$
$$x_{2} = 2 \pi n + \operatorname{asin}{\left(\frac{5}{4} \right)}$$
$$x_{2} = 2 \pi n + \operatorname{asin}{\left(\frac{5}{4} \right)}$$
$$x_{3} = 2 \pi n - \operatorname{asin}{\left(w_{1} \right)} + \pi$$
$$x_{3} = 2 \pi n - \operatorname{asin}{\left(- \frac{1}{2} \right)} + \pi$$
$$x_{3} = 2 \pi n + \frac{7 \pi}{6}$$
$$x_{4} = 2 \pi n - \operatorname{asin}{\left(w_{2} \right)} + \pi$$
$$x_{4} = 2 \pi n + \pi - \operatorname{asin}{\left(\frac{5}{4} \right)}$$
$$x_{4} = 2 \pi n + \pi - \operatorname{asin}{\left(\frac{5}{4} \right)}$$
Gráfica
Suma y producto de raíces [src]
suma
  5*pi   pi       /    /4   3*I\\         /    /4   3*I\\       /    /4   3*I\\         /    /4   3*I\\
- ---- - -- + 2*re|atan|- - ---|| + 2*I*im|atan|- - ---|| + 2*re|atan|- + ---|| + 2*I*im|atan|- + ---||
   6     6        \    \5    5 //         \    \5    5 //       \    \5    5 //         \    \5    5 //
$$\left(\left(- \frac{5 \pi}{6} - \frac{\pi}{6}\right) + \left(2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{4}{5} - \frac{3 i}{5} \right)}\right)} + 2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{4}{5} - \frac{3 i}{5} \right)}\right)}\right)\right) + \left(2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{4}{5} + \frac{3 i}{5} \right)}\right)} + 2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{4}{5} + \frac{3 i}{5} \right)}\right)}\right)$$
=
          /    /4   3*I\\       /    /4   3*I\\         /    /4   3*I\\         /    /4   3*I\\
-pi + 2*re|atan|- - ---|| + 2*re|atan|- + ---|| + 2*I*im|atan|- - ---|| + 2*I*im|atan|- + ---||
          \    \5    5 //       \    \5    5 //         \    \5    5 //         \    \5    5 //
$$- \pi + 2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{4}{5} - \frac{3 i}{5} \right)}\right)} + 2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{4}{5} + \frac{3 i}{5} \right)}\right)} + 2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{4}{5} - \frac{3 i}{5} \right)}\right)} + 2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{4}{5} + \frac{3 i}{5} \right)}\right)}$$
producto
-5*pi -pi  /    /    /4   3*I\\         /    /4   3*I\\\ /    /    /4   3*I\\         /    /4   3*I\\\
-----*----*|2*re|atan|- - ---|| + 2*I*im|atan|- - ---|||*|2*re|atan|- + ---|| + 2*I*im|atan|- + ---|||
  6    6   \    \    \5    5 //         \    \5    5 /// \    \    \5    5 //         \    \5    5 ///
$$- \frac{5 \pi}{6} \left(- \frac{\pi}{6}\right) \left(2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{4}{5} - \frac{3 i}{5} \right)}\right)} + 2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{4}{5} - \frac{3 i}{5} \right)}\right)}\right) \left(2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{4}{5} + \frac{3 i}{5} \right)}\right)} + 2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{4}{5} + \frac{3 i}{5} \right)}\right)}\right)$$
=
    2 /    /    /4   3*I\\     /    /4   3*I\\\ /    /    /4   3*I\\     /    /4   3*I\\\
5*pi *|I*im|atan|- - ---|| + re|atan|- - ---|||*|I*im|atan|- + ---|| + re|atan|- + ---|||
      \    \    \5    5 //     \    \5    5 /// \    \    \5    5 //     \    \5    5 ///
-----------------------------------------------------------------------------------------
                                            9                                            
$$\frac{5 \pi^{2} \left(\operatorname{re}{\left(\operatorname{atan}{\left(\frac{4}{5} - \frac{3 i}{5} \right)}\right)} + i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{4}{5} - \frac{3 i}{5} \right)}\right)}\right) \left(\operatorname{re}{\left(\operatorname{atan}{\left(\frac{4}{5} + \frac{3 i}{5} \right)}\right)} + i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{4}{5} + \frac{3 i}{5} \right)}\right)}\right)}{9}$$
5*pi^2*(i*im(atan(4/5 - 3*i/5)) + re(atan(4/5 - 3*i/5)))*(i*im(atan(4/5 + 3*i/5)) + re(atan(4/5 + 3*i/5)))/9
Respuesta rápida [src]
     -5*pi
x1 = -----
       6  
$$x_{1} = - \frac{5 \pi}{6}$$
     -pi 
x2 = ----
      6  
$$x_{2} = - \frac{\pi}{6}$$
         /    /4   3*I\\         /    /4   3*I\\
x3 = 2*re|atan|- - ---|| + 2*I*im|atan|- - ---||
         \    \5    5 //         \    \5    5 //
$$x_{3} = 2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{4}{5} - \frac{3 i}{5} \right)}\right)} + 2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{4}{5} - \frac{3 i}{5} \right)}\right)}$$
         /    /4   3*I\\         /    /4   3*I\\
x4 = 2*re|atan|- + ---|| + 2*I*im|atan|- + ---||
         \    \5    5 //         \    \5    5 //
$$x_{4} = 2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{4}{5} + \frac{3 i}{5} \right)}\right)} + 2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{4}{5} + \frac{3 i}{5} \right)}\right)}$$
x4 = 2*re(atan(4/5 + 3*i/5)) + 2*i*im(atan(4/5 + 3*i/5))
Respuesta numérica [src]
x1 = -22940.4331552883
x2 = -15.1843644923507
x3 = 18.3259571459405
x4 = 66.497044500984
x5 = 93.7241808320955
x6 = -57.0722665402146
x7 = -25.6563400043166
x8 = 56.025068989018
x9 = 47.6474885794452
x10 = -101.054563690472
x11 = -78.0162175641465
x12 = 5.75958653158129
x13 = -82.2050077689329
x14 = 28.7979326579064
x15 = 97.9129710368819
x16 = -0.523598775598299
x17 = 68.5914396033772
x18 = -90.5825881785057
x19 = 43.4586983746588
x20 = 100.007366139275
x21 = -46.6002910282486
x22 = 30.8923277602996
x23 = 37.1755130674792
x24 = 21071.1855264023
x25 = -63.3554518473942
x26 = -27.7507351067098
x27 = -34.0339204138894
x28 = -44.5058959258554
x29 = -18102.38046876
x30 = 91.6297857297023
x31 = -65.4498469497874
x32 = 72.7802298081635
x33 = 60.2138591938044
x34 = -71.733032256967
x35 = -31.9395253114962
x36 = -113.620934304831
x37 = 53.9306738866248
x38 = 3.66519142918809
x39 = 22.5147473507269
x40 = -1024.68280384587
x41 = -84.2994028713261
x42 = -88.4881930761125
x43 = -40.317105721069
x44 = -69.6386371545737
x45 = -50.789081233035
x46 = -6.80678408277789
x47 = -19.3731546971371
x48 = -103.148958792865
x49 = 87.4409955249159
x50 = 16.2315620435473
x51 = -38.2227106186758
x52 = 62.3082542961976
x53 = 49.7418836818384
x54 = 85.3466004225227
x55 = 74.8746249105567
x56 = 12.0427718387609
x57 = -21.4675497995303
x58 = -59.1666616426078
x59 = -13.0899693899575
x60 = 41.3643032722656
x61 = 24.60914245312
x62 = -75.9218224617533
x63 = 9.94837673636768
x64 = -2.61799387799149
x64 = -2.61799387799149
Gráfico
8*cos(x)^(2)+6*sin(x)-3=0 la ecuación