Mister Exam

Derivative of x/(x²-1)

Function f() - derivative -N order at the point
v

The graph:

from to

Piecewise:

The solution

You have entered [src]
  x   
------
 2    
x  - 1
xx21\frac{x}{x^{2} - 1}
x/(x^2 - 1)
Detail solution
  1. Apply the quotient rule, which is:

    ddxf(x)g(x)=f(x)ddxg(x)+g(x)ddxf(x)g2(x)\frac{d}{d x} \frac{f{\left(x \right)}}{g{\left(x \right)}} = \frac{- f{\left(x \right)} \frac{d}{d x} g{\left(x \right)} + g{\left(x \right)} \frac{d}{d x} f{\left(x \right)}}{g^{2}{\left(x \right)}}

    f(x)=xf{\left(x \right)} = x and g(x)=x21g{\left(x \right)} = x^{2} - 1.

    To find ddxf(x)\frac{d}{d x} f{\left(x \right)}:

    1. Apply the power rule: xx goes to 11

    To find ddxg(x)\frac{d}{d x} g{\left(x \right)}:

    1. Differentiate x21x^{2} - 1 term by term:

      1. The derivative of the constant 1-1 is zero.

      2. Apply the power rule: x2x^{2} goes to 2x2 x

      The result is: 2x2 x

    Now plug in to the quotient rule:

    x21(x21)2\frac{- x^{2} - 1}{\left(x^{2} - 1\right)^{2}}

  2. Now simplify:

    x2+1(x21)2- \frac{x^{2} + 1}{\left(x^{2} - 1\right)^{2}}


The answer is:

x2+1(x21)2- \frac{x^{2} + 1}{\left(x^{2} - 1\right)^{2}}

The graph
02468-8-6-4-2-1010-10050
The first derivative [src]
               2  
  1         2*x   
------ - ---------
 2               2
x  - 1   / 2    \ 
         \x  - 1/ 
2x2(x21)2+1x21- \frac{2 x^{2}}{\left(x^{2} - 1\right)^{2}} + \frac{1}{x^{2} - 1}
The second derivative [src]
    /          2 \
    |       4*x  |
2*x*|-3 + -------|
    |           2|
    \     -1 + x /
------------------
             2    
    /      2\     
    \-1 + x /     
2x(4x2x213)(x21)2\frac{2 x \left(\frac{4 x^{2}}{x^{2} - 1} - 3\right)}{\left(x^{2} - 1\right)^{2}}
The third derivative [src]
  /                    /          2 \\
  |                  2 |       2*x  ||
  |               4*x *|-1 + -------||
  |          2         |           2||
  |       4*x          \     -1 + x /|
6*|-1 + ------- - -------------------|
  |           2               2      |
  \     -1 + x          -1 + x       /
--------------------------------------
                       2              
              /      2\               
              \-1 + x /               
6(4x2(2x2x211)x21+4x2x211)(x21)2\frac{6 \left(- \frac{4 x^{2} \left(\frac{2 x^{2}}{x^{2} - 1} - 1\right)}{x^{2} - 1} + \frac{4 x^{2}}{x^{2} - 1} - 1\right)}{\left(x^{2} - 1\right)^{2}}
The graph
Derivative of x/(x²-1)