In order to find the extrema, we need to solve the equation
dxdf(x)=0(the derivative equals zero),
and the roots of this equation are the extrema of this function:
dxdf(x)=the first derivativex5cos(5x)−x2sin(5x)=0Solve this equationThe roots of this equation
x1=−54.3488169238437x2=−71.9419157645404x3=14.1343371423239x4=58.118775848386x5=38.0122188249304x6=71.3135923350694x7=−100.844727531359x8=146.083784576627x9=71.9419157645404x10=−36.1272083288406x11=26.0736849410777x12=−51.8355071162431x13=12.2489460520749x14=39.8972241329727x15=4.07426059185751x16=−29.843789916824x17=17.9048441860834x18=90.1632655190998x19=76.3401775129436x20=5.33321085176253x21=−61.8887289567295x22=49.9505224039313x23=2.18082433188578x24=16.019625725789x25=−5.96231975817859x26=65.0303528338626x27=81.9950804255155x28=−9.73482884639088x29=70.0569452125131x30=−4.07426059185751x31=92.0482301960676x32=21.6751439303349x33=−73.8268855526477x34=54.3488169238437x35=−87.6499786753114x36=−76.3401775129436x37=−93.9331945084242x38=−14.1343371423239x39=46.1805458475896x40=−48.0655354076095x41=5.96231975817859x42=27.9587439619171x43=−7.84888647223284x44=−41.7822249551553x45=44.2955533965743x46=1062.80075707302x47=−53.7204897849762x48=48.0655354076095x49=−68.8002977224212x50=−26.0736849410777x51=88.2783004541645x52=−16.019625725789x53=93.9331945084242x54=10.3633964974559x55=34.2421917878891x56=−75.7118546338925x57=−95.8181584776878x58=−49.9505224039313x59=80.1101133548396x60=100.216406513801x61=32.3571681455931x62=−17.2764444069457x63=−85.7650130531989x64=98.3314432704416x65=61.8887289567295x66=−97.703122123716x67=−63.773703652162x68=−11.6204509508991x69=22.3035144492262x70=−31.7288251346527x71=−17.9048441860834x72=−43.6672218724157x73=−92.0482301960676x74=−27.9587439619171x75=−81.9950804255155x76=−33.6138514218278x77=−39.8972241329727x78=78.2251457309749x79=−80.1101133548396x80=36.1272083288406x81=56.2337971862508x82=60.0037530610651x83=−60.0037530610651x84=−21.6751439303349x85=83.2517248505282x86=83.8800469802968x87=66.2870015560186x88=24.1886097994303x89=23.5602471676449x90=−236.561757726314x91=68.1719738331978x92=−58.118775848386x93=−38.0122188249304x94=−19.7900125648664x95=−83.8800469802968x96=−70.0569452125131x97=−65.6586772507346The values of the extrema at the points:
(-54.34881692384368, 0.0183995399663786)
(-71.94191576454038, 0.0139000487426319)
(14.1343371423239, 0.0707426103243319)
(58.118775848386036, 0.0172060416694555)
(38.012218824930414, 0.0263069662778767)
(71.31359233506937, -0.0140225170914689)
(-100.84472753135903, 0.00991621533273093)
(146.08378457662738, 0.00684538031180583)
(71.94191576454038, 0.0139000487426319)
(-36.12720832884058, -0.0276795446699501)
(26.073684941077683, -0.0383517168648523)
(-51.835507116243086, 0.0192916518473169)
(12.24894605207488, -0.0816287966049891)
(39.89722413297267, -0.0250640854717266)
(4.074260591857513, 0.245148120070371)
(-29.843789916823965, -0.0335070561774695)
(17.904844186083437, 0.0558473231708678)
(90.16326551909978, -0.0110909640866485)
(76.34017751294361, -0.0130992172245699)
(5.3332108517625345, 0.187372599969656)
(-61.88872895672949, 0.0161579466125529)
(49.950522403931345, -0.0200196501680894)
(2.18082433188578, -0.456626014115288)
(16.019625725789023, -0.062418566608895)
(-5.962319758178592, -0.167625675106994)
(65.03035283386262, -0.0153773619109585)
(81.9950804255155, 0.0121958173593689)
(-9.734828846390878, -0.102702270208769)
(70.0569452125131, -0.014274044093581)
(-4.074260591857513, 0.245148120070371)
(92.04823019606764, 0.0108638442847289)
(21.675143930334936, 0.0461338312539098)
(-73.82688555264774, -0.0135451512424658)
(54.34881692384368, 0.0183995399663786)
(-87.64997867531142, -0.0114089861949842)
(-76.34017751294361, -0.0130992172245699)
(-93.9331945084242, -0.010645839722077)
(-14.1343371423239, 0.0707426103243319)
(46.18054584758957, -0.0216539368199916)
(-48.06553540760948, 0.0208047478246456)
(5.962319758178592, -0.167625675106994)
(27.95874396191708, 0.0357660707790884)
(-7.848886472232839, 0.127365265464404)
(-41.782224955155264, 0.0239333483294491)
(44.29555339657426, 0.0225753993413768)
(1062.8007570730222, -0.000940910114749811)
(-53.720489784976216, -0.0186147422297532)
(48.06553540760948, 0.0208047478246456)
(-68.80029772242119, -0.0145347594110856)
(-26.073684941077683, -0.0383517168648523)
(88.27830045416445, 0.011327783027977)
(-16.019625725789023, -0.062418566608895)
(93.9331945084242, -0.010645839722077)
(10.363396497455934, 0.0964754974379398)
(34.242191787889126, 0.0292032399521732)
(-75.71185463389251, 0.0132079251768918)
(-95.81815847768776, 0.0104364124453132)
(-49.950522403931345, -0.0200196501680894)
(80.11011335483961, -0.0124827795358379)
(100.21640651380112, -0.00997838620861423)
(32.357168145593135, -0.0309044627639139)
(-17.276444406945743, -0.0578784022923388)
(-85.76501305319893, 0.0116597344932234)
(98.3314432704416, 0.0101696659613288)
(61.88872895672949, 0.0161579466125529)
(-97.70312212371603, -0.0102350660155981)
(-63.773703652162, -0.0156803670673403)
(-11.62045095089912, 0.0860424373581397)
(22.303514449226203, -0.0448341807024664)
(-31.728825134652688, 0.0315164564026059)
(-17.904844186083437, 0.0558473231708678)
(-43.66722187241573, -0.022900231996764)
(-92.04823019606764, 0.0108638442847289)
(-27.95874396191708, 0.0357660707790884)
(-81.9950804255155, 0.0121958173593689)
(-33.61385142182776, -0.0297491140511871)
(-39.89722413297267, -0.0250640854717266)
(78.22514573097487, 0.0127835713472473)
(-80.11011335483961, -0.0124827795358379)
(36.12720832884058, -0.0276795446699501)
(56.23379718625078, -0.0177827876733487)
(60.00375306106511, -0.0166655316404624)
(-60.00375306106511, -0.0166655316404624)
(-21.675143930334936, 0.0461338312539098)
(83.25172485052818, 0.012011728479606)
(83.88004698029675, -0.0119217524719224)
(66.28700155601862, -0.0150858452616839)
(24.1886097994303, 0.0413403592517879)
(23.560247167644878, -0.0424428472388261)
(-236.56175772631389, 0.00422722443484859)
(68.17197383319782, 0.0146687214750408)
(-58.118775848386036, 0.0172060416694555)
(-38.012218824930414, 0.0263069662778767)
(-19.790012564866377, -0.0505279586825202)
(-83.88004698029675, -0.0119217524719224)
(-70.0569452125131, -0.014274044093581)
(-65.65867725073458, 0.0152302087504037)
Intervals of increase and decrease of the function:Let's find intervals where the function increases and decreases, as well as minima and maxima of the function, for this let's look how the function behaves itself in the extremas and at the slightest deviation from:
Minima of the function at points:
x1=71.3135923350694x2=−36.1272083288406x3=26.0736849410777x4=12.2489460520749x5=39.8972241329727x6=−29.843789916824x7=90.1632655190998x8=76.3401775129436x9=49.9505224039313x10=2.18082433188578x11=16.019625725789x12=−5.96231975817859x13=65.0303528338626x14=−9.73482884639088x15=70.0569452125131x16=−73.8268855526477x17=−87.6499786753114x18=−76.3401775129436x19=−93.9331945084242x20=46.1805458475896x21=5.96231975817859x22=1062.80075707302x23=−53.7204897849762x24=−68.8002977224212x25=−26.0736849410777x26=−16.019625725789x27=93.9331945084242x28=−49.9505224039313x29=80.1101133548396x30=100.216406513801x31=32.3571681455931x32=−17.2764444069457x33=−97.703122123716x34=−63.773703652162x35=22.3035144492262x36=−43.6672218724157x37=−33.6138514218278x38=−39.8972241329727x39=−80.1101133548396x40=36.1272083288406x41=56.2337971862508x42=60.0037530610651x43=−60.0037530610651x44=83.8800469802968x45=66.2870015560186x46=23.5602471676449x47=−19.7900125648664x48=−83.8800469802968x49=−70.0569452125131Maxima of the function at points:
x49=−54.3488169238437x49=−71.9419157645404x49=14.1343371423239x49=58.118775848386x49=38.0122188249304x49=−100.844727531359x49=146.083784576627x49=71.9419157645404x49=−51.8355071162431x49=4.07426059185751x49=17.9048441860834x49=5.33321085176253x49=−61.8887289567295x49=81.9950804255155x49=−4.07426059185751x49=92.0482301960676x49=21.6751439303349x49=54.3488169238437x49=−14.1343371423239x49=−48.0655354076095x49=27.9587439619171x49=−7.84888647223284x49=−41.7822249551553x49=44.2955533965743x49=48.0655354076095x49=88.2783004541645x49=10.3633964974559x49=34.2421917878891x49=−75.7118546338925x49=−95.8181584776878x49=−85.7650130531989x49=98.3314432704416x49=61.8887289567295x49=−11.6204509508991x49=−31.7288251346527x49=−17.9048441860834x49=−92.0482301960676x49=−27.9587439619171x49=−81.9950804255155x49=78.2251457309749x49=−21.6751439303349x49=83.2517248505282x49=24.1886097994303x49=−236.561757726314x49=68.1719738331978x49=−58.118775848386x49=−38.0122188249304x49=−65.6586772507346Decreasing at intervals
[1062.80075707302,∞)Increasing at intervals
(−∞,−97.703122123716]