sin(pi/2*(x+3))=0

с изменением знака при 0

Получим:
$$sin{left (frac{pi}{2} left(x + 3right) right )} = 0$$

Разделим обе части ур-ния на -1

Ур-ние превратится в
$$cos{left (frac{pi x}{2} right )} = 0$$
Это ур-ние преобразуется в
$$frac{pi x}{2} = pi n + {acos}{left (0 right )}$$
$$frac{pi x}{2} = pi n – pi + {acos}{left (0 right )}$$
Или
$$frac{pi x}{2} = pi n + frac{pi}{2}$$
$$frac{pi x}{2} = pi n – frac{pi}{2}$$
, где n – любое целое число
Разделим обе части полученного ур-ния на
$$frac{pi}{2}$$
получим ответ:
$$x_{1} = frac{1}{pi} left(2 pi n + piright)$$
$$x_{2} = frac{1}{pi} left(2 pi n – piright)$$

x2 = 3

x1 = -37.0000000000000

x2 = 3.00000000000000

x3 = 91.0000000000000

x4 = -79.0000000000000

x5 = 45.0000000000000

x6 = 21.0000000000000

x7 = -7.00000000000000

x8 = 1.00000000000000

x9 = -63.0000000000000

x10 = -23.0000000000000

x11 = 89.0000000000000

x12 = 47.0000000000000

x13 = 81.0000000000000

x14 = -3.00000000000000

x15 = 67.0000000000000

x16 = -59.0000000000000

x17 = -55.0000000000000

x18 = -77.0000000000000

x19 = 83.0000000000000

x20 = -29.0000000000000

x21 = -81.0000000000000

x22 = 65.0000000000000

x23 = -75.0000000000000

x24 = -19.0000000000000

x25 = 39.0000000000000

x26 = -39.0000000000000

x27 = -65.0000000000000

x28 = 59.0000000000000

x29 = 5.00000000000000

x30 = -11.0000000000000

x31 = -89.0000000000000

x32 = -1.00000000000000

x33 = -47.0000000000000

x34 = 69.0000000000000

x35 = 71.0000000000000

x36 = 27.0000000000000

x37 = -5.00000000000000

x38 = -9.00000000000000

x39 = 85.0000000000000

x40 = -51.0000000000000

x41 = -35.0000000000000

x42 = 99.0000000000000

x43 = -87.0000000000000

x44 = 35.0000000000000

x45 = -41.0000000000000

x46 = 11.0000000000000

x47 = 61.0000000000000

x48 = -53.0000000000000

x49 = 37.0000000000000

x50 = -17.0000000000000

x51 = -71.0000000000000

x52 = 43.0000000000000

x53 = 73.0000000000000

x54 = 103.000000000000

x55 = 95.0000000000000

x56 = 31.0000000000000

x57 = -67.0000000000000

x58 = -43.0000000000000

x59 = -15.0000000000000

x60 = -21.0000000000000

x61 = -49.0000000000000

x62 = -31.0000000000000

x63 = 23.0000000000000

x64 = -95.0000000000000

x65 = 105.000000000000

x66 = -85.0000000000000

x67 = -69.0000000000000

x68 = -13.0000000000000

x69 = 53.0000000000000

x70 = 33.0000000000000

x71 = 17.0000000000000

x72 = -27.0000000000000

x73 = 13.0000000000000

x74 = 7.00000000000000

x75 = 75.0000000000000

x76 = 51.0000000000000

x77 = 97.0000000000000

x78 = 29.0000000000000

x79 = -93.0000000000000

x80 = 101.000000000000

x81 = -57.0000000000000

x82 = 63.0000000000000

x83 = 19.0000000000000

x84 = 25.0000000000000

x85 = -83.0000000000000

x86 = -61.0000000000000

x87 = 57.0000000000000

x88 = 9.00000000000000

x89 = -25.0000000000000

x90 = -45.0000000000000

x91 = 87.0000000000000

x92 = 41.0000000000000

x93 = 77.0000000000000

x94 = 93.0000000000000

x95 = 15.0000000000000

x96 = 49.0000000000000

x97 = -73.0000000000000

x98 = -33.0000000000000

x99 = 79.0000000000000

x100 = 55.0000000000000

x101 = -91.0000000000000