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: xcos(x)+x=0 Solve this equation The points of intersection with the axis X:
Numerical solution x1=0
The points of intersection with the Y axis coordinate
The graph crosses Y axis when x equals 0: substitute x = 0 to x + sqrt(x)*cos(x). 0cos(0) The result: f(0)=0 The point:
(0, 0)
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 −xsin(x)+1+2xcos(x)=0 Solve this equation The roots of this equation x1=84.7200461068506 x2=21.7982825070044 x3=46.9881328578849 x4=44.1446958001951 x5=94.3562071406871 x6=78.4330374018336 x7=97.2929565639277 x8=34.4007372254998 x9=72.1455583293193 x10=88.0770257646166 x11=28.1023797507614 x12=37.8755093111662 x13=15.4834271109676 x14=56.6906897945907 x15=69.2427218976821 x16=2.68206122525946 x17=40.6955962399499 x18=53.2790328573571 x19=9.14286874974213 x20=59.5687272757879 x21=65.857502723781 x22=81.7983135531006 x23=50.4166979783446 x24=12.8872266727419 x25=19.1064585315631 x26=62.9661476727656 x27=75.520168975823 x28=31.6105338836827 x29=25.3523559763918 x30=91.0066650197939 x31=100.635781498703 x32=6.75104176504286 The values of the extrema at the points:
(84.7200461068506, 75.5644360576617)
(21.79828250700435, 17.2159851852599)
(46.98813285788495, 40.1964135628577)
(44.1446958001951, 50.7014215532442)
(94.35620714068712, 104.012875610689)
(78.4330374018336, 69.6272348959494)
(97.29295656392769, 87.4750483550338)
(34.40073722549983, 28.6074607167868)
(72.14555832931933, 63.7040452908452)
(88.07702576461655, 97.4027076211084)
(28.102379750761397, 22.87939211233)
(37.87550931116622, 43.9343165901878)
(15.483427110967554, 11.6473043335045)
(56.690689794590654, 64.144205164234)
(69.24272189768206, 77.496204408866)
(2.6820612252594644, 1.21425555206754)
(40.69559623994987, 34.383331130769)
(53.27903285735705, 46.0395372966015)
(9.142868749742126, 6.23850907997821)
(59.56872727578785, 51.9075783817589)
(65.85750272378104, 57.7967239323487)
(81.7983135531006, 90.7808235550524)
(50.416697978344615, 57.4361440556216)
(12.887226672741932, 16.2938984057417)
(19.10645853156311, 23.3340998397661)
(62.96614767276555, 70.8298211871434)
(75.52016897582297, 84.1458683922881)
(31.610533883682674, 37.1267296651837)
(25.352355976391834, 30.2665321917206)
(91.0066650197939, 81.5141284232659)
(100.63578149870287, 110.61246371051)
(6.751041765042861, 9.07009990034565)
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=84.7200461068506 x2=21.7982825070044 x3=46.9881328578849 x4=78.4330374018336 x5=97.2929565639277 x6=34.4007372254998 x7=72.1455583293193 x8=28.1023797507614 x9=15.4834271109676 x10=2.68206122525946 x11=40.6955962399499 x12=53.2790328573571 x13=9.14286874974213 x14=59.5687272757879 x15=65.857502723781 x16=91.0066650197939 Maxima of the function at points: x16=44.1446958001951 x16=94.3562071406871 x16=88.0770257646166 x16=37.8755093111662 x16=56.6906897945907 x16=69.2427218976821 x16=81.7983135531006 x16=50.4166979783446 x16=12.8872266727419 x16=19.1064585315631 x16=62.9661476727656 x16=75.520168975823 x16=31.6105338836827 x16=25.3523559763918 x16=100.635781498703 x16=6.75104176504286 Decreasing at intervals [97.2929565639277,∞) Increasing at intervals (−∞,2.68206122525946]
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 −(xcos(x)+xsin(x)+4x23cos(x))=0 Solve this equation The roots of this equation x1=80.1230923289863 x2=−61.2773734476957 x3=−73.8409685283396 x4=39.2953468672842 x5=−80.1230923289863 x6=36.1559611393004 x7=−70.6999773315004 x8=−83.2642142711524 x9=67.559042028453 x10=−29.8785771570692 x11=−17.3363302997334 x12=4.91125081295869 x13=−2.0090972384408 x14=45.5750291575042 x15=−14.2073505099925 x16=17.3363302997334 x17=−48.7152085571549 x18=−39.2953468672842 x19=−11.0853581860961 x20=−124.100967466518 x21=−76.9820087826371 x22=−133.525176756856 x23=−92.6877714581404 x24=−4.91125081295869 x25=−23.6042658400483 x26=92.6877714581404 x27=−67.559042028453 x28=26.7409029817025 x29=−20.4691384083001 x30=48.7152085571549 x31=7.97819025123437 x32=−54.9960510556604 x33=11.0853581860961 x34=23.6042658400483 x35=−89.5465571901753 x36=−86.4053704242642 x37=89.5465571901753 x38=−36.1559611393004 x39=20.4691384083001 x40=83.2642142711524 x41=98.9702720305701 x42=29.8785771570692 x43=42.4350586138523 x44=−33.0169941017832 x45=76.9820087826371 x46=−98.9702720305701 x47=−45.5750291575042 x48=−64.4181707871237 x49=51.8555589377593 x50=−7.97819025123437 x51=64.4181707871237 x52=33.0169941017832 x53=58.136661973445 x54=73.8409685283396 x55=70.6999773315004 x56=−26.7409029817025 x57=−42.4350586138523 x58=2.0090972384408 x59=54.9960510556604 x60=−58.136661973445 x61=86.4053704242642 x62=−51.8555589377593 x63=−95.8290105250036 x64=14.2073505099925 x65=95.8290105250036 x66=61.2773734476957
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 [95.8290105250036,∞) Convex at the intervals (−∞,2.0090972384408]
Horizontal asymptotes
Let’s find horizontal asymptotes with help of the limits of this function at x->+oo and x->-oo x→−∞lim(xcos(x)+x)=−∞ Let's take the limit so, horizontal asymptote on the left doesn’t exist x→∞lim(xcos(x)+x)=∞ Let's take the limit so, horizontal asymptote on the right doesn’t exist
Inclined asymptotes
Inclined asymptote can be found by calculating the limit of x + sqrt(x)*cos(x), divided by x at x->+oo and x ->-oo
True
Let's take the limit so, inclined asymptote equation on the left: y=xx→−∞lim(xxcos(x)+x)
True
Let's take the limit so, inclined asymptote equation on the right: y=xx→∞lim(xxcos(x)+x)
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: xcos(x)+x=−x+−xcos(x) - No xcos(x)+x=x−−xcos(x) - No so, the function not is neither even, nor odd