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3sin^2(x)+cos^2(x)-2=0 la ecuación

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Solución numérica:

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Solución

Ha introducido [src]
     2         2           
3*sin (x) + cos (x) - 2 = 0
$$\left(3 \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}\right) - 2 = 0$$
Solución detallada
Tenemos la ecuación
$$\left(3 \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}\right) - 2 = 0$$
cambiamos
$$- \cos{\left(2 x \right)} = 0$$
$$2 \sin^{2}{\left(x \right)} - 1 = 0$$
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
$$a = 2$$
$$b = 0$$
$$c = -1$$
, entonces
D = b^2 - 4 * a * c = 

(0)^2 - 4 * (2) * (-1) = 8

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

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

o
$$w_{1} = \frac{\sqrt{2}}{2}$$
$$w_{2} = - \frac{\sqrt{2}}{2}$$
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:
$$x_{1} = 2 \pi n + \operatorname{asin}{\left(w_{1} \right)}$$
$$x_{1} = 2 \pi n + \operatorname{asin}{\left(\frac{\sqrt{2}}{2} \right)}$$
$$x_{1} = 2 \pi n + \frac{\pi}{4}$$
$$x_{2} = 2 \pi n + \operatorname{asin}{\left(w_{2} \right)}$$
$$x_{2} = 2 \pi n + \operatorname{asin}{\left(- \frac{\sqrt{2}}{2} \right)}$$
$$x_{2} = 2 \pi n - \frac{\pi}{4}$$
$$x_{3} = 2 \pi n - \operatorname{asin}{\left(w_{1} \right)} + \pi$$
$$x_{3} = 2 \pi n - \operatorname{asin}{\left(\frac{\sqrt{2}}{2} \right)} + \pi$$
$$x_{3} = 2 \pi n + \frac{3 \pi}{4}$$
$$x_{4} = 2 \pi n - \operatorname{asin}{\left(w_{2} \right)} + \pi$$
$$x_{4} = 2 \pi n - \operatorname{asin}{\left(- \frac{\sqrt{2}}{2} \right)} + \pi$$
$$x_{4} = 2 \pi n + \frac{5 \pi}{4}$$
Gráfica
Respuesta rápida [src]
     -3*pi
x1 = -----
       4  
$$x_{1} = - \frac{3 \pi}{4}$$
     -pi 
x2 = ----
      4  
$$x_{2} = - \frac{\pi}{4}$$
     pi
x3 = --
     4 
$$x_{3} = \frac{\pi}{4}$$
     3*pi
x4 = ----
      4  
$$x_{4} = \frac{3 \pi}{4}$$
x4 = 3*pi/4
Suma y producto de raíces [src]
suma
  3*pi   pi   pi   3*pi
- ---- - -- + -- + ----
   4     4    4     4  
$$\left(\left(- \frac{3 \pi}{4} - \frac{\pi}{4}\right) + \frac{\pi}{4}\right) + \frac{3 \pi}{4}$$
=
0
$$0$$
producto
-3*pi -pi  pi 3*pi
-----*----*--*----
  4    4   4   4  
$$\frac{3 \pi}{4} \frac{\pi}{4} \cdot - \frac{3 \pi}{4} \left(- \frac{\pi}{4}\right)$$
=
    4
9*pi 
-----
 256 
$$\frac{9 \pi^{4}}{256}$$
9*pi^4/256
Respuesta numérica [src]
x1 = 55.7632696012188
x2 = -33.7721210260903
x3 = 3.92699081698724
x4 = -16.4933614313464
x5 = -47.9092879672443
x6 = 46.3384916404494
x7 = 16.4933614313464
x8 = -76.1836218495525
x9 = 90.3207887907066
x10 = 60.4756585816035
x11 = -99.7455667514759
x12 = -98.174770424681
x13 = -10.2101761241668
x14 = -85.6083998103219
x15 = -2.35619449019234
x16 = -55.7632696012188
x17 = 63.6172512351933
x18 = 32.2013246992954
x19 = 18.0641577581413
x20 = 87.1791961371168
x21 = -82.4668071567321
x22 = -91.8915851175014
x23 = -1145.89592039688
x24 = -12256.1383398172
x25 = 77.7544181763474
x26 = -90.3207887907066
x27 = -60.4756585816035
x28 = -13.3517687777566
x29 = 91.8915851175014
x30 = -3.92699081698724
x31 = -71.4712328691678
x32 = 40.0553063332699
x33 = -25.9181393921158
x34 = 49.4800842940392
x35 = 33.7721210260903
x36 = 2.35619449019234
x37 = 47.9092879672443
x38 = 99.7455667514759
x39 = 96.6039740978861
x40 = -11.7809724509617
x41 = -62.0464549083984
x42 = -18.0641577581413
x43 = 82.4668071567321
x44 = 54.1924732744239
x45 = 5.49778714378214
x46 = -49.4800842940392
x47 = 84.037603483527
x48 = 88.7499924639117
x49 = -77.7544181763474
x50 = -46.3384916404494
x51 = 24.3473430653209
x52 = -38.484510006475
x53 = 22.776546738526
x54 = 19.6349540849362
x55 = 44.7676953136546
x56 = 162.577419823272
x57 = 85.6083998103219
x58 = 62.0464549083984
x59 = -57.3340659280137
x60 = 76.1836218495525
x61 = 69.9004365423729
x62 = 8.63937979737193
x63 = -69.9004365423729
x64 = 68.329640215578
x65 = -63.6172512351933
x66 = 98.174770424681
x67 = 41.6261026600648
x68 = -19.6349540849362
x69 = -24.3473430653209
x70 = -93.4623814442964
x71 = -41.6261026600648
x72 = -27.4889357189107
x73 = 30.6305283725005
x74 = -84.037603483527
x75 = 10.2101761241668
x76 = 384.059701901352
x77 = 25.9181393921158
x78 = 74.6128255227576
x79 = -68.329640215578
x80 = -79.3252145031423
x81 = -40.0553063332699
x82 = 52.621676947629
x83 = 11.7809724509617
x84 = -54.1924732744239
x85 = -32.2013246992954
x86 = 27.4889357189107
x87 = 38.484510006475
x88 = -5.49778714378214
x89 = -35.3429173528852
x90 = 66.7588438887831
x90 = 66.7588438887831