Let's find the inflection points, we'll need to solve the equation for this
dx2d2f(x)=0(the second derivative equals zero),
the roots of this equation will be the inflection points for the specified function graph:
dx2d2f(x)=the second derivativex32cos(x1)−xsin(x1)=0Solve this equationThe roots of this equation
x1=33124.297012115x2=39904.771377312x3=14479.7313150492x4=21259.0191811792x5=−36383.2913419629x6=−27060.3085181287x7=−18585.4480940284x8=28886.5862895034x9=25496.4920696083x10=−32145.5241220507x11=17869.2283625365x12=−31297.9789349291x13=19564.09661214x14=15327.0673496263x15=−39773.5440970563x16=38209.640819107x17=−14348.5424650725x18=−38925.9782260908x19=−37230.8517263672x20=−25365.273191964x21=20411.5519538498x22=−12653.9899632038x23=−19432.887686874x24=−17738.0242579883x25=11937.9523841008x26=−40621.1115695252x27=41599.9082873259x28=−11806.7845665482x29=23801.4794641224x30=16174.4315462694x31=36514.5174977468x32=32276.7483423665x33=−33840.6233739026x34=−26212.7880538116x35=−32993.0723444395x36=42447.4788863631x37=37362.078192229x38=24648.982396646x39=−24517.764514177x40=−13501.2455714192x41=−41468.6805452608x42=−21975.2827488203x43=33971.8484557919x44=−20280.3410578956x45=−21127.8065465298x46=−15195.8737165349x47=−42316.2509339008x48=−34688.1770045647x49=−16890.6185554691x50=18716.6547734102x51=−30450.4370366936x52=13632.4287111505x53=−38078.4140636161x54=28039.0554132717x55=17021.8196886792x56=22953.9840195429x57=35666.9588734903x58=30581.6602478055x59=27191.5291133465x60=−22822.7684696829x61=29734.1213504079x62=39057.2052525216x63=−23670.2626854463x64=22106.496925216x65=−29602.8987100326x66=−28755.3642709925x67=−16043.2338667424x68=31429.2026711056x69=26344.0078318137x70=−35535.7330502043x71=12785.166209279x72=40752.3390879025x73=34819.4024707177x74=−27907.8340740483You also need to calculate the limits of y '' for arguments seeking to indeterminate points of a function:
Points where there is an indetermination:
x1=0True
True
- the limits are not equal, so
x1=0- is an inflection point
Сonvexity and concavity intervals:Let’s find the intervals where the function is convex or concave, for this look at the behaviour of the function at the inflection points:
Have no bends at the whole real axis