Mister Exam

Derivative of (2x+1)/(x+2)

Function f() - derivative -N order at the point
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The graph:

from to

Piecewise:

The solution

You have entered [src]
2*x + 1
-------
 x + 2 
2x+1x+2\frac{2 x + 1}{x + 2}
(2*x + 1)/(x + 2)
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)=2x+1f{\left(x \right)} = 2 x + 1 and g(x)=x+2g{\left(x \right)} = x + 2.

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

    1. Differentiate 2x+12 x + 1 term by term:

      1. The derivative of the constant 11 is zero.

      2. The derivative of a constant times a function is the constant times the derivative of the function.

        1. Apply the power rule: xx goes to 11

        So, the result is: 22

      The result is: 22

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

    1. Differentiate x+2x + 2 term by term:

      1. The derivative of the constant 22 is zero.

      2. Apply the power rule: xx goes to 11

      The result is: 11

    Now plug in to the quotient rule:

    3(x+2)2\frac{3}{\left(x + 2\right)^{2}}


The answer is:

3(x+2)2\frac{3}{\left(x + 2\right)^{2}}

The graph
02468-8-6-4-2-1010-500500
The first derivative [src]
  2     2*x + 1 
----- - --------
x + 2          2
        (x + 2) 
2x+22x+1(x+2)2\frac{2}{x + 2} - \frac{2 x + 1}{\left(x + 2\right)^{2}}
The second derivative [src]
  /     1 + 2*x\
2*|-2 + -------|
  \      2 + x /
----------------
           2    
    (2 + x)     
2(2+2x+1x+2)(x+2)2\frac{2 \left(-2 + \frac{2 x + 1}{x + 2}\right)}{\left(x + 2\right)^{2}}
The third derivative [src]
  /    1 + 2*x\
6*|2 - -------|
  \     2 + x /
---------------
           3   
    (2 + x)    
6(22x+1x+2)(x+2)3\frac{6 \left(2 - \frac{2 x + 1}{x + 2}\right)}{\left(x + 2\right)^{3}}
The graph
Derivative of (2x+1)/(x+2)