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 derivative25x1cos(2x)−5x2sin(2x)=0Solve this equationThe roots of this equation
x1=−3.86262591846885x2=22.7655670069956x3=60.4715244985757x4=98.172223901556x5=74.6094747920599x6=2.24670472895453x7=−41.6200962353617x8=−60.4715244985757x9=13.3330271294063x10=−93.4597065202651x11=76.1803402100956x12=18.0503111221878x13=54.1878598258373x14=82.4637755597094x15=77.7512028363303x16=−19.6222161805821x17=−32.1935597952787x18=−57.3297052975115x19=−2.24670472895453x20=−24.3370721159772x21=−49.4750314121659x22=−98.172223901556x23=−99.7430603324317x24=33.7647173885721x25=−46.3330961388114x26=−85.6054794697228x27=−69.8968599047927x28=204.987701063789x29=68.3259813506395x30=90.3180208221014x31=−27.4798391439445x32=−652.665490738742x33=30.6223651301872x34=−84.0346285545694x35=32.1935597952787x36=−40.0490643144726x37=−10.1856514796438x38=−33.7647173885721x39=41.6200962353617x40=−5.45206082971445x41=40.0490643144726x42=3.86262591846885x43=11.7597262493445x44=85.6054794697228x45=52.6169257678188x46=−38.4780131551656x47=−25.9084912436398x48=−90.3180208221014x49=−71.4677348441946x50=46.3330961388114x51=−13.3330271294063x52=−16.4781945199112x53=19.6222161805821x54=91.8888644664832x55=−35.3358428558098x56=25.9084912436398x57=−58.9006179191122x58=−68.3259813506395x59=−76.1803402100956x60=−55.7587861230655x61=10.1856514796438x62=8.61037763596538x63=66.7550989265392x64=−77.7512028363303x65=63.6133213216672x66=62.0424254948814x67=55.7587861230655x68=−79.3220628366317x69=−63.6133213216672x70=−18.0503111221878x71=16.4781945199112x72=24.3370721159772x73=−62.0424254948814x74=96.6013861664138x75=99.7430603324317x76=88.7471755026564x77=51.0459832324538x78=−11.7597262493445x79=38.4780131551656x80=−54.1878598258373x81=−82.4637755597094x82=69.8968599047927x83=84.0346285545694x84=44.7621104652086x85=−91.8888644664832x86=47.9040693934309x87=−47.9040693934309The values of the extrema at the points:
(-3.8626259184688534, 0.0513498214103597)
(22.76556700699564, 0.00878307929139297)
(60.47152449857575, 0.00330722874014303)
(98.172223901556, 0.0020372096927757)
(74.60947479205991, -0.00268056449419756)
(2.246704728954532, -0.0868934512844887)
(-41.6200962353617, 0.00480502419282109)
(-60.47152449857575, 0.00330722874014303)
(13.333027129406338, 0.0149898079975725)
(-93.45970652026512, -0.00213992901717524)
(76.18034021009562, 0.00262529271726657)
(18.050311122187804, -0.0110758929204597)
(54.18785982583734, 0.00369070650031279)
(82.46377555970939, 0.0024252627583641)
(77.75120283633034, -0.00257225428487172)
(-19.622216180582097, 0.0101892212371523)
(-32.19355979527871, 0.00621167352298453)
(-57.32970529751154, 0.00348846017908172)
(-2.246704728954532, -0.0868934512844887)
(-24.337072115977193, -0.00821618161670149)
(-49.47503141216594, -0.00404223669460161)
(-98.172223901556, 0.0020372096927757)
(-99.74306033243167, -0.00200512683773813)
(33.76471738857206, -0.00592269357861969)
(-46.33309613881142, -0.0043163175398137)
(-85.60547946972281, 0.00233625919617385)
(-69.8968599047927, 0.00286128566232707)
(204.98770106378876, 0.000975665388749515)
(68.3259813506395, -0.00292706582698748)
(90.31802082210145, -0.00221436357359601)
(-27.479839143944467, -0.00727685852872126)
(-652.6654907387419, -0.000306435600087234)
(30.6223651301872, -0.00653030372839913)
(-84.0346285545694, -0.00237992912409497)
(32.19355979527871, 0.00621167352298453)
(-40.04906431447256, -0.0049934853287116)
(-10.18565147964378, 0.0196118496056297)
(-33.76471738857206, -0.00592269357861969)
(41.6200962353617, 0.00480502419282109)
(-5.4520608297144495, -0.0365300811292231)
(40.04906431447256, -0.0049934853287116)
(3.8626259184688534, 0.0513498214103597)
(11.759726249344503, -0.0169918467910451)
(85.60547946972281, 0.00233625919617385)
(52.6169257678188, -0.00380088664751342)
(-38.47801315516559, 0.00519733479481709)
(-25.908491243639833, 0.00771803979503518)
(-90.31802082210145, -0.00221436357359601)
(-71.46773484419464, -0.00279839715060906)
(46.33309613881142, -0.0043163175398137)
(-13.333027129406338, 0.0149898079975725)
(-16.478194519911238, 0.0121316684745241)
(19.622216180582097, 0.0101892212371523)
(91.88886446648316, 0.00217651007433517)
(-35.33584285580975, 0.00565940882594655)
(25.908491243639833, 0.00771803979503518)
(-58.90061791911219, -0.00339542777910609)
(-68.3259813506395, -0.00292706582698748)
(-76.18034021009562, 0.00262529271726657)
(-55.758786123065505, -0.00358673445619732)
(10.18565147964378, 0.0196118496056297)
(8.610377635965385, -0.0231887209384616)
(66.75509892653919, 0.00299594178340484)
(-77.75120283633034, -0.00257225428487172)
(63.613321321667165, 0.0031438984506466)
(62.04242549488138, -0.00322349592187255)
(55.758786123065505, -0.00358673445619732)
(-79.32206283663172, 0.00252131651220847)
(-63.613321321667165, 0.0031438984506466)
(-18.050311122187804, -0.0110758929204597)
(16.478194519911238, 0.0121316684745241)
(24.337072115977193, -0.00821618161670149)
(-62.04242549488138, -0.00322349592187255)
(96.60138616641379, -0.00207033593395571)
(99.74306033243167, -0.00200512683773813)
(88.7471755026564, 0.00225355708243497)
(51.04598323245382, 0.00391784805869645)
(-11.759726249344503, -0.0169918467910451)
(38.47801315516559, 0.00519733479481709)
(-54.18785982583734, 0.00369070650031279)
(-82.46377555970939, 0.0024252627583641)
(69.8968599047927, 0.00286128566232707)
(84.0346285545694, -0.00237992912409497)
(44.76211046520859, 0.00446778585366942)
(-91.88886446648316, 0.00217651007433517)
(47.90406939343085, 0.00417478325382633)
(-47.90406939343085, 0.00417478325382633)
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=74.6094747920599x2=2.24670472895453x3=−93.4597065202651x4=18.0503111221878x5=77.7512028363303x6=−2.24670472895453x7=−24.3370721159772x8=−49.4750314121659x9=−99.7430603324317x10=33.7647173885721x11=−46.3330961388114x12=68.3259813506395x13=90.3180208221014x14=−27.4798391439445x15=−652.665490738742x16=30.6223651301872x17=−84.0346285545694x18=−40.0490643144726x19=−33.7647173885721x20=−5.45206082971445x21=40.0490643144726x22=11.7597262493445x23=52.6169257678188x24=−90.3180208221014x25=−71.4677348441946x26=46.3330961388114x27=−58.9006179191122x28=−68.3259813506395x29=−55.7587861230655x30=8.61037763596538x31=−77.7512028363303x32=62.0424254948814x33=55.7587861230655x34=−18.0503111221878x35=24.3370721159772x36=−62.0424254948814x37=96.6013861664138x38=99.7430603324317x39=−11.7597262493445x40=84.0346285545694Maxima of the function at points:
x40=−3.86262591846885x40=22.7655670069956x40=60.4715244985757x40=98.172223901556x40=−41.6200962353617x40=−60.4715244985757x40=13.3330271294063x40=76.1803402100956x40=54.1878598258373x40=82.4637755597094x40=−19.6222161805821x40=−32.1935597952787x40=−57.3297052975115x40=−98.172223901556x40=−85.6054794697228x40=−69.8968599047927x40=204.987701063789x40=32.1935597952787x40=−10.1856514796438x40=41.6200962353617x40=3.86262591846885x40=85.6054794697228x40=−38.4780131551656x40=−25.9084912436398x40=−13.3330271294063x40=−16.4781945199112x40=19.6222161805821x40=91.8888644664832x40=−35.3358428558098x40=25.9084912436398x40=−76.1803402100956x40=10.1856514796438x40=66.7550989265392x40=63.6133213216672x40=−79.3220628366317x40=−63.6133213216672x40=16.4781945199112x40=88.7471755026564x40=51.0459832324538x40=38.4780131551656x40=−54.1878598258373x40=−82.4637755597094x40=69.8968599047927x40=44.7621104652086x40=−91.8888644664832x40=47.9040693934309x40=−47.9040693934309Decreasing at intervals
[99.7430603324317,∞)Increasing at intervals
(−∞,−652.665490738742]