Mister Exam

Graphing y = exp(x)*x

v

The graph:

from to

Intersection points:

does show?

Piecewise:

The solution

You have entered [src]
        x  
f(x) = e *x
f(x)=xexf{\left(x \right)} = x e^{x}
f = x*exp(x)
The graph of the function
0.01.02.03.04.05.06.07.08.09.010.00250000
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:
xex=0x e^{x} = 0
Solve this equation
The points of intersection with the axis X:

Analytical solution
x1=0x_{1} = 0
Numerical solution
x1=47.4891864944529x_{1} = -47.4891864944529
x2=109.089608132217x_{2} = -109.089608132217
x3=117.072920781941x_{3} = -117.072920781941
x4=43.5740005056864x_{4} = -43.5740005056864
x5=103.10407015753x_{5} = -103.10407015753
x6=121.065503606275x_{6} = -121.065503606275
x7=63.2896724119287x_{7} = -63.2896724119287
x8=115.076847342498x_{8} = -115.076847342498
x9=37.7592416454249x_{9} = -37.7592416454249
x10=71.2319064024203x_{10} = -71.2319064024203
x11=79.1882678183563x_{11} = -79.1882678183563
x12=89.146704685936x_{12} = -89.146704685936
x13=65.2735421114241x_{13} = -65.2735421114241
x14=105.099039845199x_{14} = -105.099039845199
x15=51.4230249783974x_{15} = -51.4230249783974
x16=49.4541901054407x_{16} = -49.4541901054407
x17=59.3262172000187x_{17} = -59.3262172000187
x18=101.109329237227x_{18} = -101.109329237227
x19=32.0913241206348x_{19} = -32.0913241206348
x20=53.3950840173982x_{20} = -53.3950840173982
x21=45.5287883412543x_{21} = -45.5287883412543
x22=87.1541152286569x_{22} = -87.1541152286569
x23=111.085180982879x_{23} = -111.085180982879
x24=57.3470343910748x_{24} = -57.3470343910748
x25=81.1789726997072x_{25} = -81.1789726997072
x26=95.1266472537626x_{26} = -95.1266472537626
x27=107.094223645316x_{27} = -107.094223645316
x28=55.369883839131x_{28} = -55.369883839131
x29=39.6870583075465x_{29} = -39.6870583075465
x30=93.1329980618501x_{30} = -93.1329980618501
x31=73.2198969347223x_{31} = -73.2198969347223
x32=91.1396752246407x_{32} = -91.1396752246407
x33=113.080930865701x_{33} = -113.080930865701
x34=0x_{34} = 0
x35=119.06914228288x_{35} = -119.06914228288
x36=35.8463765939876x_{36} = -35.8463765939876
x37=67.2586229734047x_{37} = -67.2586229734047
x38=41.6261544568938x_{38} = -41.6261544568938
x39=83.1702113647074x_{39} = -83.1702113647074
x40=61.3071694941258x_{40} = -61.3071694941258
x41=75.2086687051389x_{41} = -75.2086687051389
x42=69.2447823410302x_{42} = -69.2447823410302
x43=77.1981473783759x_{43} = -77.1981473783759
x44=85.1619388762717x_{44} = -85.1619388762717
x45=33.9540517145623x_{45} = -33.9540517145623
x46=99.1148331129772x_{46} = -99.1148331129772
x47=97.1205993527235x_{47} = -97.1205993527235
The points of intersection with the Y axis coordinate
The graph crosses Y axis when x equals 0:
substitute x = 0 to exp(x)*x.
0e00 e^{0}
The result:
f(0)=0f{\left(0 \right)} = 0
The point:
(0, 0)
Extrema of the function
In order to find the extrema, we need to solve the equation
ddxf(x)=0\frac{d}{d x} f{\left(x \right)} = 0
(the derivative equals zero),
and the roots of this equation are the extrema of this function:
ddxf(x)=\frac{d}{d x} f{\left(x \right)} =
the first derivative
xex+ex=0x e^{x} + e^{x} = 0
Solve this equation
The roots of this equation
x1=1x_{1} = -1
The values of the extrema at the points:
       -1 
(-1, -e  )


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=1x_{1} = -1
The function has no maxima
Decreasing at intervals
[1,)\left[-1, \infty\right)
Increasing at intervals
(,1]\left(-\infty, -1\right]
Inflection points
Let's find the inflection points, we'll need to solve the equation for this
d2dx2f(x)=0\frac{d^{2}}{d x^{2}} f{\left(x \right)} = 0
(the second derivative equals zero),
the roots of this equation will be the inflection points for the specified function graph:
d2dx2f(x)=\frac{d^{2}}{d x^{2}} f{\left(x \right)} =
the second derivative
(x+2)ex=0\left(x + 2\right) e^{x} = 0
Solve this equation
The roots of this equation
x1=2x_{1} = -2

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
[2,)\left[-2, \infty\right)
Convex at the intervals
(,2]\left(-\infty, -2\right]
Horizontal asymptotes
Let’s find horizontal asymptotes with help of the limits of this function at x->+oo and x->-oo
limx(xex)=0\lim_{x \to -\infty}\left(x e^{x}\right) = 0
Let's take the limit
so,
equation of the horizontal asymptote on the left:
y=0y = 0
limx(xex)=\lim_{x \to \infty}\left(x e^{x}\right) = \infty
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 exp(x)*x, divided by x at x->+oo and x ->-oo
limxex=0\lim_{x \to -\infty} e^{x} = 0
Let's take the limit
so,
inclined coincides with the horizontal asymptote on the right
limxex=\lim_{x \to \infty} e^{x} = \infty
Let's take the limit
so,
inclined asymptote on the right doesn’t exist
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:
xex=xexx e^{x} = - x e^{- x}
- No
xex=xexx e^{x} = x e^{- x}
- No
so, the function
not is
neither even, nor odd