Mister Exam

Graphing y = (2x+1)/(x-2)

v

The graph:

from to

Intersection points:

does show?

Piecewise:

The solution

You have entered [src]
       2*x + 1
f(x) = -------
        x - 2 
f(x)=2x+1x2f{\left(x \right)} = \frac{2 x + 1}{x - 2}
f = (2*x + 1)/(x - 2)
The graph of the function
0.003.000.250.500.751.001.251.501.752.002.252.502.75-100000100000
The domain of the function
The points at which the function is not precisely defined:
x1=2x_{1} = 2
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:
2x+1x2=0\frac{2 x + 1}{x - 2} = 0
Solve this equation
The points of intersection with the axis X:

Analytical solution
x1=12x_{1} = - \frac{1}{2}
Numerical solution
x1=0.5x_{1} = -0.5
The points of intersection with the Y axis coordinate
The graph crosses Y axis when x equals 0:
substitute x = 0 to (2*x + 1)/(x - 2).
02+12\frac{0 \cdot 2 + 1}{-2}
The result:
f(0)=12f{\left(0 \right)} = - \frac{1}{2}
The point:
(0, -1/2)
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
2x22x+1(x2)2=0\frac{2}{x - 2} - \frac{2 x + 1}{\left(x - 2\right)^{2}} = 0
Solve this equation
Solutions are not found,
function may have no extrema
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
2(2+2x+1x2)(x2)2=0\frac{2 \left(-2 + \frac{2 x + 1}{x - 2}\right)}{\left(x - 2\right)^{2}} = 0
Solve this equation
Solutions are not found,
maybe, the function has no inflections
Vertical asymptotes
Have:
x1=2x_{1} = 2
Horizontal asymptotes
Let’s find horizontal asymptotes with help of the limits of this function at x->+oo and x->-oo
limx(2x+1x2)=2\lim_{x \to -\infty}\left(\frac{2 x + 1}{x - 2}\right) = 2
Let's take the limit
so,
equation of the horizontal asymptote on the left:
y=2y = 2
limx(2x+1x2)=2\lim_{x \to \infty}\left(\frac{2 x + 1}{x - 2}\right) = 2
Let's take the limit
so,
equation of the horizontal asymptote on the right:
y=2y = 2
Inclined asymptotes
Inclined asymptote can be found by calculating the limit of (2*x + 1)/(x - 2), divided by x at x->+oo and x ->-oo
limx(2x+1x(x2))=0\lim_{x \to -\infty}\left(\frac{2 x + 1}{x \left(x - 2\right)}\right) = 0
Let's take the limit
so,
inclined coincides with the horizontal asymptote on the right
limx(2x+1x(x2))=0\lim_{x \to \infty}\left(\frac{2 x + 1}{x \left(x - 2\right)}\right) = 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:
2x+1x2=12xx2\frac{2 x + 1}{x - 2} = \frac{1 - 2 x}{- x - 2}
- No
2x+1x2=12xx2\frac{2 x + 1}{x - 2} = - \frac{1 - 2 x}{- x - 2}
- No
so, the function
not is
neither even, nor odd