Sr Examen

Otras calculadoras

4*cos(3*x)^2-4*cos(3*x-pi/2)-1=0 la ecuación

El profesor se sorprenderá mucho al ver tu solución correcta😉

v

Solución numérica:

Buscar la solución numérica en el intervalo [, ]

Solución

Ha introducido [src]
     2             /      pi\        
4*cos (3*x) - 4*cos|3*x - --| - 1 = 0
                   \      2 /        
$$\left(4 \cos^{2}{\left(3 x \right)} - 4 \cos{\left(3 x - \frac{\pi}{2} \right)}\right) - 1 = 0$$
Gráfica
Suma y producto de raíces [src]
suma
                  /    /        ___\\         /    /        ___\\         /    /        ___\\         /    /        ___\\
                  |    |2   I*\/ 5 ||         |    |2   I*\/ 5 ||         |    |2   I*\/ 5 ||         |    |2   I*\/ 5 ||
              2*re|atan|- - -------||   2*I*im|atan|- - -------||     2*re|atan|- + -------||   2*I*im|atan|- + -------||
pi   5*pi         \    \3      3   //         \    \3      3   //         \    \3      3   //         \    \3      3   //
-- + ---- + - ----------------------- - ------------------------- + - ----------------------- - -------------------------
18    18                 3                          3                            3                          3            
$$\left(- \frac{2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{2}{3} + \frac{\sqrt{5} i}{3} \right)}\right)}}{3} - \frac{2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{2}{3} + \frac{\sqrt{5} i}{3} \right)}\right)}}{3}\right) + \left(\left(\frac{\pi}{18} + \frac{5 \pi}{18}\right) + \left(- \frac{2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{2}{3} - \frac{\sqrt{5} i}{3} \right)}\right)}}{3} - \frac{2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{2}{3} - \frac{\sqrt{5} i}{3} \right)}\right)}}{3}\right)\right)$$
=
      /    /        ___\\       /    /        ___\\              /    /        ___\\         /    /        ___\\
      |    |2   I*\/ 5 ||       |    |2   I*\/ 5 ||              |    |2   I*\/ 5 ||         |    |2   I*\/ 5 ||
  2*re|atan|- - -------||   2*re|atan|- + -------||        2*I*im|atan|- - -------||   2*I*im|atan|- + -------||
      \    \3      3   //       \    \3      3   //   pi         \    \3      3   //         \    \3      3   //
- ----------------------- - ----------------------- + -- - ------------------------- - -------------------------
             3                         3              3                3                           3            
$$- \frac{2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{2}{3} - \frac{\sqrt{5} i}{3} \right)}\right)}}{3} - \frac{2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{2}{3} + \frac{\sqrt{5} i}{3} \right)}\right)}}{3} + \frac{\pi}{3} - \frac{2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{2}{3} + \frac{\sqrt{5} i}{3} \right)}\right)}}{3} - \frac{2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{2}{3} - \frac{\sqrt{5} i}{3} \right)}\right)}}{3}$$
producto
        /      /    /        ___\\         /    /        ___\\\ /      /    /        ___\\         /    /        ___\\\
        |      |    |2   I*\/ 5 ||         |    |2   I*\/ 5 ||| |      |    |2   I*\/ 5 ||         |    |2   I*\/ 5 |||
        |  2*re|atan|- - -------||   2*I*im|atan|- - -------||| |  2*re|atan|- + -------||   2*I*im|atan|- + -------|||
pi 5*pi |      \    \3      3   //         \    \3      3   //| |      \    \3      3   //         \    \3      3   //|
--*----*|- ----------------------- - -------------------------|*|- ----------------------- - -------------------------|
18  18  \             3                          3            / \             3                          3            /
$$\frac{\pi}{18} \frac{5 \pi}{18} \left(- \frac{2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{2}{3} - \frac{\sqrt{5} i}{3} \right)}\right)}}{3} - \frac{2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{2}{3} - \frac{\sqrt{5} i}{3} \right)}\right)}}{3}\right) \left(- \frac{2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{2}{3} + \frac{\sqrt{5} i}{3} \right)}\right)}}{3} - \frac{2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{2}{3} + \frac{\sqrt{5} i}{3} \right)}\right)}}{3}\right)$$
=
      /    /    /        ___\\     /    /        ___\\\ /    /    /        ___\\     /    /        ___\\\
    2 |    |    |2   I*\/ 5 ||     |    |2   I*\/ 5 ||| |    |    |2   I*\/ 5 ||     |    |2   I*\/ 5 |||
5*pi *|I*im|atan|- - -------|| + re|atan|- - -------|||*|I*im|atan|- + -------|| + re|atan|- + -------|||
      \    \    \3      3   //     \    \3      3   /// \    \    \3      3   //     \    \3      3   ///
---------------------------------------------------------------------------------------------------------
                                                   729                                                   
$$\frac{5 \pi^{2} \left(\operatorname{re}{\left(\operatorname{atan}{\left(\frac{2}{3} - \frac{\sqrt{5} i}{3} \right)}\right)} + i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{2}{3} - \frac{\sqrt{5} i}{3} \right)}\right)}\right) \left(\operatorname{re}{\left(\operatorname{atan}{\left(\frac{2}{3} + \frac{\sqrt{5} i}{3} \right)}\right)} + i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{2}{3} + \frac{\sqrt{5} i}{3} \right)}\right)}\right)}{729}$$
5*pi^2*(i*im(atan(2/3 - i*sqrt(5)/3)) + re(atan(2/3 - i*sqrt(5)/3)))*(i*im(atan(2/3 + i*sqrt(5)/3)) + re(atan(2/3 + i*sqrt(5)/3)))/729
Respuesta rápida [src]
     pi
x1 = --
     18
$$x_{1} = \frac{\pi}{18}$$
     5*pi
x2 = ----
      18 
$$x_{2} = \frac{5 \pi}{18}$$
           /    /        ___\\         /    /        ___\\
           |    |2   I*\/ 5 ||         |    |2   I*\/ 5 ||
       2*re|atan|- - -------||   2*I*im|atan|- - -------||
           \    \3      3   //         \    \3      3   //
x3 = - ----------------------- - -------------------------
                  3                          3            
$$x_{3} = - \frac{2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{2}{3} - \frac{\sqrt{5} i}{3} \right)}\right)}}{3} - \frac{2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{2}{3} - \frac{\sqrt{5} i}{3} \right)}\right)}}{3}$$
           /    /        ___\\         /    /        ___\\
           |    |2   I*\/ 5 ||         |    |2   I*\/ 5 ||
       2*re|atan|- + -------||   2*I*im|atan|- + -------||
           \    \3      3   //         \    \3      3   //
x4 = - ----------------------- - -------------------------
                  3                          3            
$$x_{4} = - \frac{2 \operatorname{re}{\left(\operatorname{atan}{\left(\frac{2}{3} + \frac{\sqrt{5} i}{3} \right)}\right)}}{3} - \frac{2 i \operatorname{im}{\left(\operatorname{atan}{\left(\frac{2}{3} + \frac{\sqrt{5} i}{3} \right)}\right)}}{3}$$
x4 = -2*re(atan(2/3 + sqrt(5)*i/3))/3 - 2*i*im(atan(2/3 + sqrt(5)*i/3))/3
Respuesta numérica [src]
x1 = 90.2335223281068
x2 = 19.0240888467382
x3 = 88.1391272257137
x4 = 60.9119908946021
x5 = -17.9768912955416
x6 = -39.6189740202713
x7 = 2.26892802759263
x8 = 74.176493209759
x9 = -6.10865238198015
x10 = -50.0909495322373
x11 = 37.873644768277
x12 = 32.2885911618951
x13 = 39.9680398706701
x14 = 63.0063859969953
x15 = -64.0535835481919
x16 = 28.0998009571087
x17 = 4.36332312998582
x18 = 30.1941960595019
x19 = 86.0447321233204
x20 = -80.8087443673375
x21 = -41.7133691226645
x22 = 48.3456202802429
x23 = -418.006355852642
x24 = -85.6956662729216
x25 = -83.6012711705284
x26 = 10.6465084371654
x27 = -96.1676417848876
x28 = -24.9582083035189
x29 = 99.3092344384773
x30 = 55.3269372882203
x31 = -66.1479786505851
x32 = -36.8264472170804
x33 = -34.7320521146872
x34 = 69.9877030049726
x35 = -45.9021593274509
x36 = 83.9503370209273
x37 = 81.8559419185341
x38 = -87.7900613753148
x39 = 16.929693744345
x40 = 26.0054058547155
x41 = -43.8077642250577
x42 = -4.01425727958696
x43 = -13.7881010907552
x44 = -20.0712863979348
x45 = 65.7989128001862
x46 = -78.7143492649443
x47 = -99.6583002888762
x48 = 42.0624349730633
x49 = 95.120444233691
x50 = -94.0732466824944
x51 = -59.8647933434055
x52 = 78.3652834145454
x53 = -11.693705988362
x54 = 46.2512251778497
x55 = 0.872664625997165
x56 = -61.9591884457987
x57 = 76.2708883121522
x58 = -27.0526034059121
x59 = -57.7703982410123
x60 = 23.9110107523223
x61 = 0.174532925199433
x62 = 92.3279174305
x63 = -68.940505453776
x64 = -91.9788515801012
x65 = 9.25024503556995
x66 = -9.59931088596881
x67 = 44.1568300754565
x68 = -1.91986217719376
x69 = 56.7232006898157
x70 = 72.0820981073658
x71 = -71.0349005561692
x72 = -15.8824961931484
x73 = 53.2325421858271
x74 = 97.2148393360842
x75 = -47.9965544298441
x76 = -55.6760031386191
x77 = -89.884456477708
x78 = -53.5816080362259
x79 = 7.15584993317675
x80 = 67.8933079025794
x81 = 34.3829862642883
x81 = 34.3829862642883