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 derivative((tanh2(x)−1)sinh(tanh(x))+2cosh(tanh(x))tanh(x))(tanh2(x)−1)=0Solve this equationThe roots of this equation
x1=−22.36613259083x2=−72x3=−62x4=−44x5=−54x6=31.8870724794909x7=−98x8=96x9=64x10=28.6760419286256x11=20.6753972494872x12=−31.976245996576x13=54x14=62x15=40x16=−48x17=−96x18=0x19=−40x20=18.6753976927522x21=100x22=78x23=−30.3746613927776x24=−32x25=80x26=−20.3661326061554x27=−52x28=32.468253968254x29=70x30=16.6754218978551x31=−100x32=−16.3661781103476x33=32x34=44x35=60x36=90x37=−32.2038153090912x38=76x39=72x40=86x41=56x42=−58x43=−31.7529322617035x44=32.000015780841x45=−86x46=−56x47=42x48=−26.3661315069563x49=31.7312936927894x50=98x51=22.6753972443119x52=−80x53=−76x54=84x55=−84x56=94x57=58x58=31.7787220654169x59=−38x60=34x61=30.6502781482389x62=−18.3661334245818x63=−82x64=−92x65=38x66=−42x67=88x68=−78x69=−36x70=−60x71=−28.3660709532537x72=92x73=−64x74=−88x75=24.6753973204929x76=−24.3661326142577x77=−66x78=36x79=−46x80=26.6753908017134x81=66x82=−34x83=52x84=−94x85=−90x86=68x87=82x88=74x89=−68x90=−74x91=46x92=50x93=−31.3350186083881x94=−70x95=−50x96=48x97=−31.5673076923077Сonvexity 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
(−∞,0]Convex at the intervals
[0,∞)