Graph of the function intersects the axis X at f = 0
so we need to solve the equation:
$$2 \cos{\left(x - 1 \right)} + 1 = 0$$
Solve this equationThe points of intersection with the axis X:
Analytical solution$$x_{1} = 1 + \frac{2 \pi}{3}$$
$$x_{2} = 1 + \frac{4 \pi}{3}$$
Numerical solution$$x_{1} = -59.7374579694027$$
$$x_{2} = -45.0766922526503$$
$$x_{3} = -63.9262481741891$$
$$x_{4} = -19.943951023932$$
$$x_{5} = 84.7758040957278$$
$$x_{6} = -91.1533845053006$$
$$x_{7} = 97.342174710087$$
$$x_{8} = 15.6607657167524$$
$$x_{9} = -7.37758040957278$$
$$x_{10} = 93.1533845053006$$
$$x_{11} = -32.5103216382911$$
$$x_{12} = -40.8879020478639$$
$$x_{13} = -53.4542726622231$$
$$x_{14} = 40.7935069454707$$
$$x_{15} = -11537.0226190841$$
$$x_{16} = 99.4365698124802$$
$$x_{17} = 49.1710873550435$$
$$x_{18} = 9.37758040957278$$
$$x_{19} = -26.2271363311115$$
$$x_{20} = 65.9262481741891$$
$$x_{21} = 24.0383461263252$$
$$x_{22} = -70.2094334813686$$
$$x_{23} = -13.6607657167524$$
$$x_{24} = 72.2094334813686$$
$$x_{25} = -3.18879020478639$$
$$x_{26} = 53.3598775598299$$
$$x_{27} = -72.3038285837618$$
$$x_{28} = -15.7551608191456$$
$$x_{29} = 17.7551608191456$$
$$x_{30} = -51.3598775598299$$
$$x_{31} = -76.4926187885482$$
$$x_{32} = 78.4926187885482$$
$$x_{33} = -78.5870138909414$$
$$x_{34} = 11.471975511966$$
$$x_{35} = -97.4365698124802$$
$$x_{36} = 91.0589894029074$$
$$x_{37} = -82.7758040957278$$
$$x_{38} = 36.6047167406843$$
$$x_{39} = -1.0943951023932$$
$$x_{40} = 5.18879020478639$$
$$x_{41} = 21.943951023932$$
$$x_{42} = 34.5103216382911$$
$$x_{43} = 3.0943951023932$$
$$x_{44} = 80.5870138909414$$
$$x_{45} = 47.0766922526503$$
$$x_{46} = -66.0206432765823$$
$$x_{47} = -34.6047167406843$$
$$x_{48} = -95.342174710087$$
$$x_{49} = -22.0383461263252$$
$$x_{50} = 68.0206432765823$$
$$x_{51} = -38.7935069454707$$
$$x_{52} = -47.1710873550435$$
$$x_{53} = -89.0589894029074$$
$$x_{54} = 61.7374579694027$$
$$x_{55} = 28.2271363311115$$
$$x_{56} = 1330.94089001968$$
$$x_{57} = -28.3215314335047$$
$$x_{58} = 55.4542726622231$$
$$x_{59} = 59.6430628670095$$
$$x_{60} = -57.6430628670095$$
$$x_{61} = -103.71975511966$$
$$x_{62} = 30.3215314335047$$
$$x_{63} = -84.870199198121$$
$$x_{64} = 74.3038285837618$$
$$x_{65} = 42.8879020478639$$
$$x_{66} = 86.870199198121$$
$$x_{67} = -9.47197551196598$$