Mister Exam

Derivative of x*ln^2x

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

The graph:

from to

Piecewise:

The solution

You have entered [src]
     2   
x*log (x)
xlog(x)2x \log{\left(x \right)}^{2}
d /     2   \
--\x*log (x)/
dx           
ddxxlog(x)2\frac{d}{d x} x \log{\left(x \right)}^{2}
Detail solution
  1. Apply the product rule:

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

    f(x)=xf{\left(x \right)} = x; to find ddxf(x)\frac{d}{d x} f{\left(x \right)}:

    1. Apply the power rule: xx goes to 11

    g(x)=log(x)2g{\left(x \right)} = \log{\left(x \right)}^{2}; to find ddxg(x)\frac{d}{d x} g{\left(x \right)}:

    1. Let u=log(x)u = \log{\left(x \right)}.

    2. Apply the power rule: u2u^{2} goes to 2u2 u

    3. Then, apply the chain rule. Multiply by ddxlog(x)\frac{d}{d x} \log{\left(x \right)}:

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

      The result of the chain rule is:

      2log(x)x\frac{2 \log{\left(x \right)}}{x}

    The result is: log(x)2+2log(x)\log{\left(x \right)}^{2} + 2 \log{\left(x \right)}

  2. Now simplify:

    (log(x)+2)log(x)\left(\log{\left(x \right)} + 2\right) \log{\left(x \right)}


The answer is:

(log(x)+2)log(x)\left(\log{\left(x \right)} + 2\right) \log{\left(x \right)}

The graph
02468-8-6-4-2-1010-50100
The first derivative [src]
   2              
log (x) + 2*log(x)
log(x)2+2log(x)\log{\left(x \right)}^{2} + 2 \log{\left(x \right)}
The second derivative [src]
2*(1 + log(x))
--------------
      x       
2(log(x)+1)x\frac{2 \left(\log{\left(x \right)} + 1\right)}{x}
The third derivative [src]
-2*log(x)
---------
     2   
    x    
2log(x)x2- \frac{2 \log{\left(x \right)}}{x^{2}}
The graph
Derivative of x*ln^2x