Mister Exam

Derivative of 4x^2log0,5x

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

from to

Piecewise:

The solution

You have entered [src]
   2           
4*x *log(0.5*x)
4x2log(0.5x)4 x^{2} \log{\left(0.5 x \right)}
(4*x^2)*log(0.5*x)
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)=4x2f{\left(x \right)} = 4 x^{2}; to find ddxf(x)\frac{d}{d x} f{\left(x \right)}:

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

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

      So, the result is: 8x8 x

    g(x)=log(0.5x)g{\left(x \right)} = \log{\left(0.5 x \right)}; to find ddxg(x)\frac{d}{d x} g{\left(x \right)}:

    1. Let u=0.5xu = 0.5 x.

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

    3. Then, apply the chain rule. Multiply by ddx0.5x\frac{d}{d x} 0.5 x:

      1. 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: 0.50.5

      The result of the chain rule is:

      1.0x\frac{1.0}{x}

    The result is: 8xlog(0.5x)+4.0x8 x \log{\left(0.5 x \right)} + 4.0 x

  2. Now simplify:

    x(8.0log(x)1.54517744447956)x \left(8.0 \log{\left(x \right)} - 1.54517744447956\right)


The answer is:

x(8.0log(x)1.54517744447956)x \left(8.0 \log{\left(x \right)} - 1.54517744447956\right)

The graph
02468-8-6-4-2-1010-5001000
The first derivative [src]
4.0*x + 8*x*log(0.5*x)
8xlog(0.5x)+4.0x8 x \log{\left(0.5 x \right)} + 4.0 x
The second derivative [src]
12.0 + 8*log(0.5*x)
8log(0.5x)+12.08 \log{\left(0.5 x \right)} + 12.0
The third derivative [src]
8.0
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 x 
8.0x\frac{8.0}{x}