The points at which the function is not precisely defined: x1=0
The points of intersection with the X-axis coordinate
Graph of the function intersects the axis X at f = 0 so we need to solve the equation: xsin(x)=0 Solve this equation The points of intersection with the axis X:
The points of intersection with the Y axis coordinate
The graph crosses Y axis when x equals 0: substitute x = 0 to sin(x)/sqrt(x). 0sin(0) The result: f(0)=NaN - the solutions of the equation d'not exist
Extrema of the function
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 derivative xcos(x)−2x23sin(x)=0 Solve this equation The roots of this equation x1=−39.2571723324086 x2=−26.6848024909251 x3=−58.1108600600615 x4=−1.16556118520721 x5=−7.78988375114457 x6=7.78988375114457 x7=−51.8266315338985 x8=67.5368388204916 x9=−80.1043708909521 x10=−67.5368388204916 x11=20.3958423573092 x12=64.3948849627586 x13=117.80548025038 x14=70.6787605627689 x15=−45.5421150692309 x16=32.9715594404485 x17=4.60421677720058 x18=−23.5407082923052 x19=−64.3948849627586 x20=−70.6787605627689 x21=−76.9625234358705 x22=−73.8206542907788 x23=73.8206542907788 x24=48.6844162648433 x25=80.1043708909521 x26=−20.3958423573092 x27=−92.6715879363332 x28=26.6848024909251 x29=−36.1144715353049 x30=158.64727737108 x31=92.6715879363332 x32=10.9499436485412 x33=83.2461991121237 x34=−98.9551158352145 x35=54.9687756155963 x36=−29.8283692130955 x37=14.1017251335659 x38=−4.60421677720058 x39=215.19677332017 x40=−61.2528940466862 x41=−83.2461991121237 x42=−246.612995841404 x43=−54.9687756155963 x44=76.9625234358705 x45=36.1144715353049 x46=−48.6844162648433 x47=29.8283692130955 x48=58.1108600600615 x49=−42.3997088362447 x50=17.2497818346079 x51=−32.9715594404485 x52=23.5407082923052 x53=1.16556118520721 x54=−17.2497818346079 x55=−10.9499436485412 x56=51.8266315338985 x57=45.5421150692309 x58=−86.3880101981266 x59=89.5298059530594 x60=−95.8133575027966 x61=39.2571723324086 x62=−89.5298059530594 x63=61.2528940466862 x64=95.8133575027966 x65=−14.1017251335659 x66=98.9551158352145 x67=86.3880101981266 x68=42.3997088362447 The values of the extrema at the points:
(-39.25717233240859, 0.159589851348603*I)
(-26.68480249092507, 0.19354937797769*I)
(-58.110860060061505, 0.131176268600912*I)
(-1.1655611852072114, 0.851241066782324*I)
(-7.789883751144573, 0.357554083426262*I)
(7.789883751144573, 0.357554083426262)
(-51.82663153389846, 0.138900336703391*I)
(67.53683882049161, -0.121679588990783)
(-80.1043708909521, -0.111728362291416*I)
(-67.53683882049161, -0.121679588990783*I)
(20.395842357309167, 0.221359780635401)
(64.39488496275855, 0.124612389237314)
(117.80548025038037, -0.0921326029924126)
(70.67876056276886, 0.118944583684481)
(-45.5421150692309, 0.148172370731446*I)
(32.97155944044848, 0.17413269656851)
(4.604216777200577, -0.463314891176637)
(-23.54070829230515, -0.206059336815155*I)
(-64.39488496275855, 0.124612389237314*I)
(-70.67876056276886, 0.118944583684481*I)
(-76.96252343587051, 0.113985913925499*I)
(-73.82065429077876, -0.116386094038002*I)
(73.82065429077876, -0.116386094038002)
(48.68441626484328, -0.143311853691665)
(80.1043708909521, -0.111728362291416)
(-20.395842357309167, 0.221359780635401*I)
(-92.67158793633321, -0.103877233902111*I)
(26.68480249092507, 0.19354937797769)
(-36.11447153530485, -0.166386370791913*I)
(158.6472773710796, 0.0793928754394215)
(92.67158793633321, -0.103877233902111)
(10.94994364854116, -0.301885161430297)
(83.24619911212368, 0.109599849994829)
(-98.95511583521451, -0.100525289012326*I)
(54.96877561559635, -0.134872684738376)
(-29.828369213095506, -0.183072974858657*I)
(14.101725133565873, 0.266128298234218)
(-4.604216777200577, -0.463314891176637*I)
(215.1967733201699, 0.0681680624478802)
(-61.252894046686194, -0.127768037744087*I)
(-83.24619911212368, 0.109599849994829*I)
(-246.61299584140428, 0.0636782512070729*I)
(-54.96877561559635, -0.134872684738376*I)
(76.96252343587051, 0.113985913925499)
(36.11447153530485, -0.166386370791913)
(-48.68441626484328, -0.143311853691665*I)
(29.828369213095506, -0.183072974858657)
(58.110860060061505, 0.131176268600912)
(-42.39970883624466, -0.15356362930828*I)
(17.249781834607894, -0.240672145897842)
(-32.97155944044848, 0.17413269656851*I)
(23.54070829230515, -0.206059336815155)
(1.1655611852072114, 0.851241066782324)
(-17.249781834607894, -0.240672145897842*I)
(-10.94994364854116, -0.301885161430297*I)
(51.82663153389846, 0.138900336703391)
(45.5421150692309, 0.148172370731446)
(-86.38801019812658, -0.107588534144322*I)
(89.52980595305935, 0.105684039776562)
(-95.81335750279658, 0.102160040658152*I)
(39.25717233240859, 0.159589851348603)
(-89.52980595305935, 0.105684039776562*I)
(61.252894046686194, -0.127768037744087)
(95.81335750279658, 0.102160040658152)
(-14.101725133565873, 0.266128298234218*I)
(98.95511583521451, -0.100525289012326)
(86.38801019812658, -0.107588534144322)
(42.39970883624466, -0.15356362930828)
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=67.5368388204916 x2=117.80548025038 x3=4.60421677720058 x4=73.8206542907788 x5=48.6844162648433 x6=80.1043708909521 x7=92.6715879363332 x8=10.9499436485412 x9=54.9687756155963 x10=36.1144715353049 x11=29.8283692130955 x12=17.2497818346079 x13=23.5407082923052 x14=61.2528940466862 x15=98.9551158352145 x16=86.3880101981266 x17=42.3997088362447 Maxima of the function at points: x17=7.78988375114457 x17=20.3958423573092 x17=64.3948849627586 x17=70.6787605627689 x17=32.9715594404485 x17=26.6848024909251 x17=158.64727737108 x17=83.2461991121237 x17=14.1017251335659 x17=215.19677332017 x17=76.9625234358705 x17=58.1108600600615 x17=1.16556118520721 x17=51.8266315338985 x17=45.5421150692309 x17=89.5298059530594 x17=39.2571723324086 x17=95.8133575027966 Decreasing at intervals [117.80548025038,∞) Increasing at intervals (−∞,4.60421677720058]
Inflection points
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 x−sin(x)−xcos(x)+4x23sin(x)=0 Solve this equation The roots of this equation x1=12.4860672578708 x2=−47.1026555912318 x3=−37.6725595300203 x4=−28.2389032383054 x5=169.640108376141 x6=37.6725595300203 x7=−43.9595440566684 x8=53.3883416918471 x9=−94.2371675854493 x10=25.0928628865337 x11=−84.8112100697664 x12=62.8159318625173 x13=−147.648081727825 x14=−87.95322400825 x15=−40.8161982919721 x16=43.9595440566684 x17=65.9582831752547 x18=91.0952088771736 x19=81.6691637048431 x20=−31.3840497369889 x21=15.6439318755503 x22=−59.6735006001685 x23=−56.5309760413753 x24=−9.31693112610028 x25=28.2389032383054 x26=−62.8159318625173 x27=−75.384957467622 x28=31.3840497369889 x29=75.384957467622 x30=−78.5270810189266 x31=−113.088492608463 x32=−69.1005654545348 x33=−91.0952088771736 x34=−81.6691637048431 x35=72.2427877152145 x36=2.75936321522763 x37=−65.9582831752547 x38=−6.11791002392407 x39=18.796291187414 x40=−25.0928628865337 x41=40.8161982919721 x42=9.31693112610028 x43=78.5270810189266 x44=59.6735006001685 x45=−18.796291187414 x46=97.3791026663451 x47=56.5309760413753 x48=87.95322400825 x49=−97.3791026663451 x50=−100.521016336234 x51=21.9455418081046 x52=69.1005654545348 x53=34.5285475249278 x54=−2.75936321522763 x55=−50.2455769233645 x56=100.521016336234 x57=84.8112100697664 x58=−53.3883416918471 x59=6.11791002392407 x60=47.1026555912318 x61=−12.4860672578708 x62=94.2371675854493 x63=−34.5285475249278 x64=−15.6439318755503 x65=−72.2427877152145 x66=−21.9455418081046 x67=50.2455769233645 You also need to calculate the limits of y '' for arguments seeking to indeterminate points of a function: Points where there is an indetermination: x1=0
x→0−lim(x−sin(x)−xcos(x)+4x23sin(x))=−∞i x→0+lim(x−sin(x)−xcos(x)+4x23sin(x))=−∞ - the limits are not equal, so x1=0 - is an inflection point
Сonvexity 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 [97.3791026663451,∞) Convex at the intervals (−∞,2.75936321522763]
Vertical asymptotes
Have: x1=0
Horizontal asymptotes
Let’s find horizontal asymptotes with help of the limits of this function at x->+oo and x->-oo x→−∞lim(xsin(x))=0 Let's take the limit so, equation of the horizontal asymptote on the left: y=0 x→∞lim(xsin(x))=0 Let's take the limit so, equation of the horizontal asymptote on the right: y=0
Inclined asymptotes
Inclined asymptote can be found by calculating the limit of sin(x)/sqrt(x), divided by x at x->+oo and x ->-oo x→−∞lim(xxsin(x))=0 Let's take the limit so, inclined coincides with the horizontal asymptote on the right x→∞lim(xxsin(x))=0 Let's take the limit so, inclined coincides with the horizontal asymptote on the left
Even and odd functions
Let's check, whether the function even or odd by using relations f = f(-x) и f = -f(-x). So, check: xsin(x)=−−xsin(x) - No xsin(x)=−xsin(x) - No so, the function not is neither even, nor odd