cosx=-1/2 (уравнение)

Найду корень уравнения: cosx=-1/2

Вы ввели

cos(x) = -1/2

$$\cos{\left(x \right)} = - \frac{1}{2}$$

Подробное решение

Дано уравнение
$$\cos{\left(x \right)} = - \frac{1}{2}$$
- это простейшее тригонометрическое ур-ние
Это ур-ние преобразуется в
$$x = \pi n + \operatorname{acos}{\left(- \frac{1}{2} \right)}$$
$$x = \pi n - \pi + \operatorname{acos}{\left(- \frac{1}{2} \right)}$$
Или
$$x = \pi n + \frac{2 \pi}{3}$$
$$x = \pi n - \frac{\pi}{3}$$
, где n - любое целое число

Быстрый ответ

     2*pi
x1 = ----
      3  

$$x_{1} = \frac{2 \pi}{3}$$

     4*pi
x2 = ----
      3  

$$x_{2} = \frac{4 \pi}{3}$$

Сумма и произведение корней

сумма

2*pi   4*pi
---- + ----
 3      3  

$$\frac{2 \pi}{3} + \frac{4 \pi}{3}$$

=

2*pi

$$2 \pi$$

произведение

2*pi 4*pi
----*----
 3    3  

$$\frac{2 \pi}{3} \frac{4 \pi}{3}$$

=

    2
8*pi 
-----
  9  

$$\frac{8 \pi^{2}}{9}$$

Численный ответ

x1 = -98.4365698124802

x2 = 71.2094334813686

x3 = 60.7374579694027

x4 = -71.2094334813686

x5 = -8.37758040957278

x6 = 23.0383461263252

x7 = 27.2271363311115

x8 = -64.9262481741891

x9 = 2.0943951023932

x10 = 630.412925820352

x11 = 79.5870138909414

x12 = 35.6047167406843

x13 = 77.4926187885482

x14 = 41.8879020478639

x15 = -41.8879020478639

x16 = -92.1533845053006

x17 = 14.6607657167524

x18 = 64.9262481741891

x19 = 58.6430628670095

x20 = -73.3038285837618

x21 = -79.5870138909414

x22 = -48.1710873550435

x23 = 96.342174710087

x24 = 8.37758040957278

x25 = 73.3038285837618

x26 = -27.2271363311115

x27 = 46.0766922526503

x28 = 16.7551608191456

x29 = 416.784625376246

x30 = -10.471975511966

x31 = -23.0383461263252

x32 = -39.7935069454707

x33 = 54.4542726622231

x34 = -85.870199198121

x35 = -83.7758040957278

x36 = -16.7551608191456

x37 = 48.1710873550435

x38 = 33.5103216382911

x39 = -60.7374579694027

x40 = -67.0206432765823

x41 = -4.18879020478639

x42 = 117.286125734019

x43 = -33.5103216382911

x44 = 98.4365698124802

x45 = -14.6607657167524

x46 = -35.6047167406843

x47 = 92.1533845053006

x48 = -46.0766922526503

x49 = -2.0943951023932

x50 = -1623.15620435473

x51 = -77.4926187885482

x52 = -29.3215314335047

x53 = -58.6430628670095

x54 = -90.0589894029074

x55 = 4.18879020478639

x56 = 90.0589894029074

x57 = -54.4542726622231

x58 = 20.943951023932

x59 = -52.3598775598299

x60 = 83.7758040957278

x61 = 67.0206432765823

x62 = -96.342174710087

x63 = -20.943951023932

x64 = 10.471975511966

x65 = 39.7935069454707

x66 = 29.3215314335047

x67 = 52.3598775598299

x68 = 85.870199198121

График