Mister Exam

Derivative of ln(√x+√(x+1))

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

The graph:

from to

Piecewise:

The solution

You have entered [src]
   /  ___     _______\
log\\/ x  + \/ x + 1 /
log(x+x+1)\log{\left(\sqrt{x} + \sqrt{x + 1} \right)}
log(sqrt(x) + sqrt(x + 1))
Detail solution
  1. Let u=x+x+1u = \sqrt{x} + \sqrt{x + 1}.

  2. The derivative of log(u)\log{\left(u \right)} is 1u\frac{1}{u}.

  3. Then, apply the chain rule. Multiply by ddx(x+x+1)\frac{d}{d x} \left(\sqrt{x} + \sqrt{x + 1}\right):

    1. Differentiate x+x+1\sqrt{x} + \sqrt{x + 1} term by term:

      1. Apply the power rule: x\sqrt{x} goes to 12x\frac{1}{2 \sqrt{x}}

      2. Let u=x+1u = x + 1.

      3. Apply the power rule: u\sqrt{u} goes to 12u\frac{1}{2 \sqrt{u}}

      4. Then, apply the chain rule. Multiply by ddx(x+1)\frac{d}{d x} \left(x + 1\right):

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

          1. Apply the power rule: xx goes to 11

          2. The derivative of the constant 11 is zero.

          The result is: 11

        The result of the chain rule is:

        12x+1\frac{1}{2 \sqrt{x + 1}}

      The result is: 12x+1+12x\frac{1}{2 \sqrt{x + 1}} + \frac{1}{2 \sqrt{x}}

    The result of the chain rule is:

    12x+1+12xx+x+1\frac{\frac{1}{2 \sqrt{x + 1}} + \frac{1}{2 \sqrt{x}}}{\sqrt{x} + \sqrt{x + 1}}

  4. Now simplify:

    12xx+1\frac{1}{2 \sqrt{x} \sqrt{x + 1}}


The answer is:

12xx+1\frac{1}{2 \sqrt{x} \sqrt{x + 1}}

The graph
02468-8-6-4-2-10105-5
The first derivative [src]
   1           1     
------- + -----------
    ___       _______
2*\/ x    2*\/ x + 1 
---------------------
    ___     _______  
  \/ x  + \/ x + 1   
12x+1+12xx+x+1\frac{\frac{1}{2 \sqrt{x + 1}} + \frac{1}{2 \sqrt{x}}}{\sqrt{x} + \sqrt{x + 1}}
The second derivative [src]
 /                                       2\ 
 |                    /  1         1    \ | 
 |                    |----- + ---------| | 
 |                    |  ___     _______| | 
 | 1         1        \\/ x    \/ 1 + x / | 
-|---- + ---------- + --------------------| 
 | 3/2          3/2      ___     _______  | 
 \x      (1 + x)       \/ x  + \/ 1 + x   / 
--------------------------------------------
             /  ___     _______\            
           4*\\/ x  + \/ 1 + x /            
1(x+1)32+(1x+1+1x)2x+x+1+1x324(x+x+1)- \frac{\frac{1}{\left(x + 1\right)^{\frac{3}{2}}} + \frac{\left(\frac{1}{\sqrt{x + 1}} + \frac{1}{\sqrt{x}}\right)^{2}}{\sqrt{x} + \sqrt{x + 1}} + \frac{1}{x^{\frac{3}{2}}}}{4 \left(\sqrt{x} + \sqrt{x + 1}\right)}
The third derivative [src]
                                         3                                            
                      /  1         1    \      / 1         1     \ /  1         1    \
                    2*|----- + ---------|    3*|---- + ----------|*|----- + ---------|
                      |  ___     _______|      | 3/2          3/2| |  ___     _______|
 3         3          \\/ x    \/ 1 + x /      \x      (1 + x)   / \\/ x    \/ 1 + x /
---- + ---------- + ---------------------- + -----------------------------------------
 5/2          5/2                       2                  ___     _______            
x      (1 + x)       /  ___     _______\                 \/ x  + \/ 1 + x             
                     \\/ x  + \/ 1 + x /                                              
--------------------------------------------------------------------------------------
                                  /  ___     _______\                                 
                                8*\\/ x  + \/ 1 + x /                                 
3(x+1)52+3(1(x+1)32+1x32)(1x+1+1x)x+x+1+2(1x+1+1x)3(x+x+1)2+3x528(x+x+1)\frac{\frac{3}{\left(x + 1\right)^{\frac{5}{2}}} + \frac{3 \left(\frac{1}{\left(x + 1\right)^{\frac{3}{2}}} + \frac{1}{x^{\frac{3}{2}}}\right) \left(\frac{1}{\sqrt{x + 1}} + \frac{1}{\sqrt{x}}\right)}{\sqrt{x} + \sqrt{x + 1}} + \frac{2 \left(\frac{1}{\sqrt{x + 1}} + \frac{1}{\sqrt{x}}\right)^{3}}{\left(\sqrt{x} + \sqrt{x + 1}\right)^{2}} + \frac{3}{x^{\frac{5}{2}}}}{8 \left(\sqrt{x} + \sqrt{x + 1}\right)}