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Derivative of sqrt(1/cos(2*x-1))

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

The graph:

from to

Piecewise:

The solution

You have entered [src]
    ______________
   /      1       
  /  ------------ 
\/   cos(2*x - 1) 
$$\sqrt{\frac{1}{\cos{\left(2 x - 1 \right)}}}$$
sqrt(1/cos(2*x - 1))
Detail solution
  1. Let .

  2. Apply the power rule: goes to

  3. Then, apply the chain rule. Multiply by :

    1. Let .

    2. Apply the power rule: goes to

    3. Then, apply the chain rule. Multiply by :

      1. Let .

      2. The derivative of cosine is negative sine:

      3. Then, apply the chain rule. Multiply by :

        1. Differentiate term by term:

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

            1. Apply the power rule: goes to

            So, the result is:

          2. The derivative of the constant is zero.

          The result is:

        The result of the chain rule is:

      The result of the chain rule is:

    The result of the chain rule is:

  4. Now simplify:


The answer is:

The graph
The first derivative [src]
    ______________             
   /      1                    
  /  ------------ *sin(2*x - 1)
\/   cos(2*x - 1)              
-------------------------------
          cos(2*x - 1)         
$$\frac{\sqrt{\frac{1}{\cos{\left(2 x - 1 \right)}}} \sin{\left(2 x - 1 \right)}}{\cos{\left(2 x - 1 \right)}}$$
The second derivative [src]
    _______________ /         2          \
   /       1        |    3*sin (-1 + 2*x)|
  /  ------------- *|2 + ----------------|
\/   cos(-1 + 2*x)  |        2           |
                    \     cos (-1 + 2*x) /
$$\left(\frac{3 \sin^{2}{\left(2 x - 1 \right)}}{\cos^{2}{\left(2 x - 1 \right)}} + 2\right) \sqrt{\frac{1}{\cos{\left(2 x - 1 \right)}}}$$
The third derivative [src]
    _______________ /           2          \              
   /       1        |     15*sin (-1 + 2*x)|              
  /  ------------- *|14 + -----------------|*sin(-1 + 2*x)
\/   cos(-1 + 2*x)  |          2           |              
                    \       cos (-1 + 2*x) /              
----------------------------------------------------------
                      cos(-1 + 2*x)                       
$$\frac{\left(\frac{15 \sin^{2}{\left(2 x - 1 \right)}}{\cos^{2}{\left(2 x - 1 \right)}} + 14\right) \sqrt{\frac{1}{\cos{\left(2 x - 1 \right)}}} \sin{\left(2 x - 1 \right)}}{\cos{\left(2 x - 1 \right)}}$$