Решите уравнение cos(x)=cos(3*x) (косинус от (х) равно косинус от (3 умножить на х)) - Найдите корень уравнения подробно по-шагам. [Есть ответ!]

cos(x)=cos(3*x) (уравнение)

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    Найду корень уравнения: cos(x)=cos(3*x)

    Решение

    Вы ввели [src]
    cos(x) = cos(3*x)
    $$\cos{\left(x \right)} = \cos{\left(3 x \right)}$$
    График
    Быстрый ответ [src]
    x1 = 0
    $$x_{1} = 0$$
         -pi 
    x2 = ----
          2  
    $$x_{2} = - \frac{\pi}{2}$$
         pi
    x3 = --
         2 
    $$x_{3} = \frac{\pi}{2}$$
    x4 = pi
    $$x_{4} = \pi$$
    Сумма и произведение корней [src]
    сумма
            pi   pi     
    0 + 0 - -- + -- + pi
            2    2      
    $$\left(\left(- \frac{\pi}{2} + \left(0 + 0\right)\right) + \frac{\pi}{2}\right) + \pi$$
    =
    pi
    $$\pi$$
    произведение
        -pi  pi   
    1*0*----*--*pi
         2   2    
    $$\pi \frac{\pi}{2} 1 \cdot 0 \left(- \frac{\pi}{2}\right)$$
    =
    0
    $$0$$
    Численный ответ [src]
    x1 = -45.553093477052
    x2 = 75.3982236793524
    x3 = 86.3937979737193
    x4 = -91.1061867632284
    x5 = -81.6814090375457
    x6 = 31.4159265728873
    x7 = 37.6991119937168
    x8 = 84.8230015887783
    x9 = 36.1283155162826
    x10 = 72.2566310277219
    x11 = -7.85398163397448
    x12 = 95.8185759344887
    x13 = -73.8274273593601
    x14 = -23.5619449019235
    x15 = 97.38937222667
    x16 = 65.9734457527245
    x17 = 43.9822971693493
    x18 = -53.407075257786
    x19 = 9.42477806710815
    x20 = 94.2477792514877
    x21 = -47.1238897080294
    x22 = 56.5486676266806
    x23 = -36.1283155162826
    x24 = -58.1194640914112
    x25 = 42.4115008234622
    x26 = 2.89784959789169e-7
    x27 = -21.9911485864718
    x28 = -37.6991118769198
    x29 = -25.1327411700478
    x30 = 62.8318530302311
    x31 = 7.85398163397448
    x32 = -14.1371669411541
    x33 = 20.4203522483337
    x34 = -87.9645943590963
    x35 = -51.8362787842316
    x36 = -50.2654823143599
    x37 = -9.42477810445402
    x38 = -207.34511550934
    x39 = 14.1371669411541
    x40 = -43.9822971746609
    x41 = 53.4070751278617
    x42 = -28.2743337371269
    x43 = -65.9734457652028
    x44 = 59.6902605703693
    x45 = -97.389372410446
    x46 = -67.5442420521806
    x47 = -80.1106126665397
    x48 = -21.9911486312213
    x49 = -15.7079632963762
    x50 = -1.5707963267949
    x51 = 0.0
    x52 = 50.2654824463642
    x53 = 80.1106126665397
    x54 = 64.4026493985908
    x55 = -72.2566308917313
    x56 = -94.2477794692392
    x57 = -6.28318516003462
    x58 = 78.5398162040055
    x59 = -12.5663705453118
    x60 = 87.964594335453
    x61 = 18.8495559220487
    x62 = -69.1150382393654
    x63 = 58.1194640914112
    x64 = -78.5398162373076
    x65 = 100.530964781462
    x66 = -56.5486676717583
    x67 = 94.2477796093527
    x68 = -75.398223834204
    x69 = 81.6814091468681
    x70 = -43.982296876345
    x71 = -28.2743341715057
    x72 = 12.5663704724455
    x73 = 28.2743338652459
    x74 = -65.9734453602046
    x75 = 34.5575190494922
    x76 = 73.8274273593601
    x77 = -95.8185759344887
    x78 = 6.28318528433976
    x79 = -89.5353906273091
    x80 = -34.5575191076725
    x81 = 29.845130209103
    x82 = -906.349480560655
    x83 = -3.14159262638665
    x84 = 50.2654819973737
    x85 = 9.42477801500462
    x86 = 43.9822971001043
    x87 = 40.8407044744738
    x88 = -31.4159266812001
    x89 = 15.7079634169143
    x90 = -29.845130209103
    x91 = -100.530964804106
    x92 = -59.6902604573056
    x93 = 21.9911485851767
    x94 = 51.8362787842316
    График
    cos(x)=cos(3*x) (уравнение) /media/krcore-image-pods/hash/equation/9/c9/c88c5a62c74cbf7bed70f9c01251e.png