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 derivativexsign(x)−x∣x∣=0Solve this equationThe roots of this equation
x1=66x2=94x3=98x4=46x5=24x6=−24x7=−46x8=18x9=22x10=−82x11=−74x12=−42x13=50x14=64x15=36x16=−60x17=−66x18=−8x19=−26x20=−2x21=86x22=42x23=−36x24=100x25=−18x26=12x27=90x28=−88x29=−92x30=52x31=−44x32=6x33=38x34=96x35=−84x36=10x37=−98x38=62x39=−28x40=14x41=30x42=−14x43=−72x44=−20x45=54x46=−52x47=−12x48=68x49=32x50=28x51=−16x52=−40x53=−48x54=44x55=−6x56=−50x57=16x58=−78x59=4x60=−56x61=−10x62=74x63=−34x64=−62x65=−58x66=84x67=−68x68=76x69=−94x70=−86x71=−4x72=40x73=−96x74=−70x75=8x76=82x77=−80x78=−76x79=−38x80=−32x81=−30x82=−54x83=48x84=20x85=56x86=58x87=78x88=70x89=60x90=92x91=−90x92=72x93=88x94=2x95=−64x96=−100x97=80x98=−22x99=34x100=26Сonvexity 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
[−30,30]Convex at the intervals
(−∞,−30]∪[30,∞)