Graph of the function intersects the axis X at f = 0
so we need to solve the equation:
$$2 \sin{\left(3 x \right)} - \frac{1}{2} = 0$$
Solve this equationThe points of intersection with the axis X:
Analytical solution$$x_{1} = - \frac{\operatorname{asin}{\left(\frac{1}{4} \right)}}{3} + \frac{\pi}{3}$$
$$x_{2} = \frac{\operatorname{asin}{\left(\frac{1}{4} \right)}}{3}$$
Numerical solution$$x_{1} = 50.3497092091507$$
$$x_{2} = 39.8777336971847$$
$$x_{3} = 26.0957120282009$$
$$x_{4} = -81.5971822416206$$
$$x_{5} = -66.0576724770997$$
$$x_{6} = -15.792190019663$$
$$x_{7} = -41.8036752961499$$
$$x_{8} = -79.5027871392274$$
$$x_{9} = -99.5679941153908$$
$$x_{10} = -89.9747626511934$$
$$x_{11} = 2.17862185410722$$
$$x_{12} = 46.1609190043643$$
$$x_{13} = -6.19895855546556$$
$$x_{14} = -76.5296479890657$$
$$x_{15} = 96.426401461801$$
$$x_{16} = 28.1901071305941$$
$$x_{17} = -225.231700258983$$
$$x_{18} = 17.7181316186281$$
$$x_{19} = 85.954425949835$$
$$x_{20} = -59.7744871699201$$
$$x_{21} = -35.5204899889703$$
$$x_{22} = 16.8393875708596$$
$$x_{23} = 74.2667993832444$$
$$x_{24} = -19.9809802244494$$
$$x_{25} = -48.0868606033295$$
$$x_{26} = 98.5207965641942$$
$$x_{27} = -73.2196018320478$$
$$x_{28} = -4.10456345307237$$
$$x_{29} = -72.3408577842793$$
$$x_{30} = -11.6033998148766$$
$$x_{31} = -300.629923945138$$
$$x_{32} = 81.7656357450487$$
$$x_{33} = 8.46180716128681$$
$$x_{34} = 19.8125267210213$$
$$x_{35} = -22.0753753268426$$
$$x_{36} = 14.7449924684664$$
$$x_{37} = -45.9924655009363$$
$$x_{38} = 32.3788973353805$$
$$x_{39} = -61.8688822723133$$
$$x_{40} = -92.0691577535866$$
$$x_{41} = 2917.57660438544$$
$$x_{42} = 24.0013169258077$$
$$x_{43} = 70.078009178458$$
$$x_{44} = -68.1520675794929$$
$$x_{45} = 52.4441043115439$$
$$x_{46} = 92.2376112570146$$
$$x_{47} = 54.5384994139371$$
$$x_{48} = 78.4555895880308$$
$$x_{49} = 6.36741205889361$$
$$x_{50} = 44.0665239019711$$
$$x_{51} = -24.1697704292358$$
$$x_{52} = -13.6977949172698$$
$$x_{53} = -70.2464626818861$$
$$x_{54} = -83.6915773440138$$
$$x_{55} = -50.1812557057227$$
$$x_{56} = -87.8803675488002$$
$$x_{57} = 41.9721287995779$$
$$x_{58} = -55.5856969651337$$
$$x_{59} = 65.8892189736716$$
$$x_{60} = 4.27301695650042$$
$$x_{61} = 90.1432161546214$$
$$x_{62} = -28.3585606340222$$
$$x_{63} = -2.01016835067917$$
$$x_{64} = 94.3320063594078$$
$$x_{65} = -57.6800920675269$$
$$x_{66} = 63.7948238712784$$
$$x_{67} = 0.0842267517140262$$
$$x_{68} = 30.2845022329873$$
$$x_{69} = -39.7092801937567$$
$$x_{70} = 21.9069218234145$$
$$x_{71} = -9.50900471248341$$
$$x_{72} = -77.4083920368342$$
$$x_{73} = 82.6443797928172$$
$$x_{74} = 57.5116385640989$$
$$x_{75} = 58.7272896187235$$
$$x_{76} = 37.7833385947915$$
$$x_{77} = 83.8600308474418$$
$$x_{78} = -17.8865851220562$$
$$x_{79} = -85.785972446407$$
$$x_{80} = -43.8980703985431$$
$$x_{81} = -37.6148850913635$$
$$x_{82} = -26.264165531629$$
$$x_{83} = -33.4260948865771$$
$$x_{84} = 72.1724042808512$$
$$x_{85} = 76.3611944856376$$
$$x_{86} = -63.9632773747065$$
$$x_{87} = 10.55620226368$$
$$x_{88} = 88.0488210522282$$
$$x_{89} = 34.4732924377737$$
$$x_{90} = 61.7004287688852$$
$$x_{91} = 67.9836140760648$$
$$x_{92} = 48.2553141067575$$
$$x_{93} = -94.1635528559798$$