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 derivative2(−(x2+1)2x+(tan2(x)+1)tan(x))=0Solve this equationThe roots of this equation
x1=−91.1061882761657x2=34.5575433799626x3=−97.3893733436485x4=−25.1328040205507x5=−94.2477808019261x6=31.4159587220774x7=0x8=−21.9912422140771x9=78.5398184031738x10=9.42594558462241x11=25.1328040205507x12=−53.4070816709532x13=−9.42594558462241x14=40.8407191588716x15=59.6902651176419x16=3.16758836114823x17=−43.98230889158x18=75.3982260183446x19=−75.3982260183446x20=−34.5575433799626x21=37.6991304808952x22=−62.8318571011953x23=91.1061882761657x24=−59.6902651176419x25=94.2477808019261x26=87.9645957693188x27=18.8497043937593x28=−78.5398184031738x29=−87.9645957693188x30=−37.6991304808952x31=−56.548673291256x32=53.4070816709532x33=84.8230032850167x34=15.7082191890374x35=97.3893733436485x36=−65.9734492062964x37=−72.2566336822883x38=6.28701317511834x39=−31.4159587220774x40=−47.1238993512507x41=72.2566336822883x42=−18.8497043937593x43=12.5668681635809x44=−12.5668681635809x45=−69.1150414065892x46=100.530965898917x47=56.548673291256x48=62.8318571011953x49=−28.2743780124173x50=−6.28701317511834x51=−84.8230032850167x52=−3.16758836114823x53=47.1238993512507x54=−40.8407191588716x55=−15.7082191890374x56=65.9734492062964x57=−81.6814108277603x58=28.2743780124173x59=−50.2654903251137x60=21.9912422140771x61=81.6814108277603x62=69.1150414065892x63=50.2654903251137x64=−100.530965898917x65=43.98230889158Сonvexity 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:
Concave at the intervals
[100.530965898917,∞)Convex at the intervals
(−∞,−100.530965898917]